diff --git a/README.md b/README.md
index f87b095..cd5bc55 100644
--- a/README.md
+++ b/README.md
@@ -6,10 +6,13 @@ elements, and dependency edges show calls, imports, and inheritance. The same
 model is emitted as versioned JSON for other tools, including a future Fold
 integration.
 
-The initial extractor recognizes Rust, Dart, Python, C/C++,
-JavaScript/TypeScript, and Swift source extensions. Symbol extraction is intentionally conservative and
-lexical in v0.1; every relationship records its backend, confidence, and source
-location so consumers can distinguish it from imported symbolic evidence.
+The initial extractor provides first-class lexical profiles for Rust, Dart,
+C/C++, and JavaScript/TypeScript, with explicitly secondary Python and Swift
+coverage. Symbol extraction is intentionally conservative and lexical in v0.1;
+every relationship records its backend, confidence, and all contributing source
+locations so consumers can distinguish it from imported symbolic evidence.
+See [language support and parity](docs/architecture/language-support.md) for the
+construct-level coverage matrix and first-class promotion contract.
 
 ## Quick start
 
@@ -54,6 +57,8 @@ default; an internal or vendored URL can be supplied with --cytoscape-url.
   confidence.
 - A focused Rust test suite, quality gate, bounded auto-loop, and artifact-based
   benchmark runner.
+- A labeled language-parity corpus with independent gates for every advertised
+  language; Python and Swift remain characterization-only secondary profiles.
 
 ## Important limits
 
diff --git a/docs/ROADMAP.md b/docs/ROADMAP.md
index 78fea22..02a2151 100644
--- a/docs/ROADMAP.md
+++ b/docs/ROADMAP.md
@@ -4,7 +4,9 @@
 
 - Versioned graph JSON.
 - Fast lexical multi-language preview.
-- Dart classes, functions/methods, imports, inheritance, and local calls.
+- First-class lexical profiles for Dart, Rust, C/C++, and
+  JavaScript/TypeScript, with labeled parity fixtures and per-language gates.
+- Characterized secondary Python and Swift coverage.
 - Fold SARIF/native finding overlay.
 - Interactive Cytoscape building.
 - Transparent structural indicators and deterministic tests.
diff --git a/docs/architecture/graph-model.md b/docs/architecture/graph-model.md
index fec8732..bc64b6a 100644
--- a/docs/architecture/graph-model.md
+++ b/docs/architecture/graph-model.md
@@ -26,7 +26,10 @@ Every edge has:
 - lane: syntactic, symbolic, imported, or heuristic;
 - backend: producer and mode;
 - confidence: producer-calibrated value;
-- provenance: source location or report artifact.
+- provenance: the first source location or report artifact, retained for v0.1
+  consumers;
+- locations: every distinct source location contributing to a deduplicated
+  edge.
 
 ## Health indicator
 
@@ -50,4 +53,3 @@ should map Fold function/block/operation/value fact IDs directly to Brick
 identities and retain source/binary lanes. Source proved, latent, heuristic, and
 concrete-witness confidence must remain distinguishable. Binary evidence must
 not be promoted to symbolic evidence without corroboration.
-
diff --git a/docs/architecture/language-support.md b/docs/architecture/language-support.md
new file mode 100644
index 0000000..4b3b102
--- /dev/null
+++ b/docs/architecture/language-support.md
@@ -0,0 +1,84 @@
+# Language support and parity
+
+Brick 0.1 recognizes source-file extensions for Rust, Dart, Python, C/C++,
+JavaScript/TypeScript, and Swift. Recognition does not imply compiler-level
+coverage: the current backend is deliberately lexical, line-oriented, and
+evidence-labeled.
+
+The first-class lexical profiles are Dart, Rust, C/C++, and
+JavaScript/TypeScript. Here, parity means each profile has dedicated construct
+patterns, relationship evidence, positive and clean-negative fixtures, stable
+regression assertions, and an independent benchmark gate. It does not mean the
+languages have identical grammar features or compiler-grade resolution. Python
+and Swift remain secondary until their extraction contracts and fixtures reach
+the same standard.
+
+Plain `.h` files remain classified as C++ because their language cannot be
+determined from the extension alone. C projects that require header symbol
+resolution need compilation-database or include-context evidence in a future
+frontend; Brick does not guess that ownership.
+
+## Current coverage
+
+| Language | Useful current coverage | Important gaps | Tier |
+| --- | --- | --- | --- |
+| Dart | Classes, mixins, enums, extensions, methods, named constructors, accessors, import/export/part directives, `extends`/`with`/`implements`/`on`, and ordinary calls | operators, generic relationship targets, conditional directives, and multiline declarations | first-class lexical |
+| Rust | Structs, enums, traits, ordinary/async/const/unsafe/extern functions, simple inherent/trait impl ownership, ordinary/turbofish/macro calls, braced `use` resolution, and raw-string masking | module ownership, unions/type aliases, nested generic impl headers, glob imports, and macro definitions | first-class lexical |
+| C | Distinct `.c` identity, includes, structs/unions/enums, narrow function forms, and ordinary calls | anonymous typedef aggregates, function pointers, C23 attributes, macros, and multiline declarations | first-class lexical |
+| C++ | Classes/structs/unions/enums, `final`, constructors/destructors/operators, override-qualified methods, multiple inheritance, ordinary calls, and local include resolution | namespaces, overload disambiguation, lambdas, concepts/requires, complex template bases, and multiline declarations | first-class lexical |
+| JavaScript | Default/exported classes, inheritance, owned methods/constructors, named functions, arrows, ES imports/re-exports, CommonJS `require`, dynamic imports, ordinary calls, and multiline template masking | function expressions, computed methods, decorators, JSX structure, package exports, and type-aware member calls | first-class lexical |
+| TypeScript | JavaScript forms plus interfaces/enums/namespaces, generic and abstract classes/functions/methods, `implements`, type imports/re-exports, and typed arrows | type aliases, overload declarations, decorators, declaration merging, TSX structure, and path mappings | first-class lexical |
+| Python | Characterized fixture coverage for basic classes, functions/async functions, imports, calls, inheritance, and indentation scopes | multiple bases, qualified ownership, decorators, multiline strings, relative/dynamic imports, and complete multi-import handling | secondary |
+| Swift | Characterized extension recognition plus incidental simple `class`, `func`, inheritance, ownership, and call matching | no dedicated profile; imports, protocols, actors, enums, extensions, async/generic forms, and Swift-specific signatures are incomplete | secondary |
+
+## Cross-language invariants
+
+All extractors must satisfy these rules before first-class parity is claimed:
+
+1. Bare symbol names never resolve across language boundaries. Cross-language
+   edges require explicit import, binding, or FFI evidence.
+2. Recognized methods are owned by their enclosing type rather than only by the
+   source file.
+3. Unsupported declarations do not silently become call edges.
+4. Strings, comments, and language-specific literal forms do not create symbols
+   or calls.
+5. Duplicate names use stable qualified identities and do not resolve
+   ambiguously.
+6. Every edge retains backend, confidence, its first provenance value, and all
+   distinct source locations contributing to a deduplicated relationship.
+
+## Parity test contract
+
+Each first-class language needs deterministic positive and clean-negative
+fixtures for:
+
+- files, types, functions, methods, and containment;
+- imports and inheritance/implementation relationships;
+- local, qualified, member, ambiguous, and unresolved calls;
+- duplicate symbols, nested scopes, strings, comments, and unsupported syntax;
+- stable graph identities and evidence under repeated scans.
+
+The positive baseline corpus lives in `tests/fixtures/languages`, with its
+shared contract in `tests/language_parity.rs`. Gap slices should extend these
+fixtures with a positive construct and its nearest clean negative before
+changing extraction behavior.
+
+Real-repository benchmarks supplement these fixtures but do not replace them.
+Compare graph counts and health metrics only after confirming that analyzed
+files, constructs, and evidence coverage remain stable. A lower health score can
+be more accurate when a false resolved edge becomes an honest unresolved edge.
+
+Python and Swift fixtures intentionally describe their current secondary tier in
+the same corpus. Their assertions are characterization tests, not evidence of
+first-class parity. In particular, the Swift fixture preserves the visible gap
+between file/type recognition and Swift-specific relationship extraction.
+
+## Delivered foundation order
+
+1. Shared resolver and scope foundation.
+2. A golden fixture harness and mixed-language collision corpus.
+3. Dart and Rust parity slices.
+4. Separate C and C++ extraction profiles and parity slices.
+5. Separate JavaScript and TypeScript extraction profiles and parity slices.
+6. Explicit Python and Swift characterization, followed by a separate promotion
+   decision if warranted.
diff --git a/src/fold.rs b/src/fold.rs
index a6afd96..80452f9 100644
--- a/src/fold.rs
+++ b/src/fold.rs
@@ -57,6 +57,7 @@ pub fn import_findings(building: &mut Building, report: &Path) -> Result<usize>
             lines_of_code: 0,
             attributes,
         });
+        let provenance = format!("{}:{}", report.display(), finding.line);
         building.edges.push(Edge {
             id: stable_id("edge", &format!("{node_id}:flags:{file_id}")),
             source: node_id,
@@ -70,7 +71,8 @@ pub fn import_findings(building: &mut Building, report: &Path) -> Result<usize>
                 },
                 backend: format!("fold:discover:{}", finding.backend),
                 confidence: confidence_value(&finding.confidence),
-                provenance: format!("{}:{}", report.display(), finding.line),
+                locations: vec![provenance.clone()],
+                provenance,
             },
         });
         imported += 1;
diff --git a/src/model.rs b/src/model.rs
index 026fac9..db32c7c 100644
--- a/src/model.rs
+++ b/src/model.rs
@@ -72,6 +72,8 @@ pub struct Evidence {
     pub backend: String,
     pub confidence: f64,
     pub provenance: String,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub locations: Vec<String>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
@@ -142,10 +144,12 @@ pub fn stable_id(kind: &str, identity: &str) -> String {
 }
 
 pub fn evidence(backend: &str, confidence: f64, provenance: impl Into<String>) -> Evidence {
+    let provenance = provenance.into();
     Evidence {
         lane: EvidenceLane::Syntactic,
         backend: backend.into(),
         confidence,
-        provenance: provenance.into(),
+        locations: vec![provenance.clone()],
+        provenance,
     }
 }
diff --git a/src/scan.rs b/src/scan.rs
index 3b6ca53..21c70fc 100644
--- a/src/scan.rs
+++ b/src/scan.rs
@@ -94,7 +94,7 @@ struct ScanState {
     nodes: Vec<Node>,
     edges: Vec<Edge>,
     edge_keys: HashSet<(String, String, EdgeKind)>,
-    symbols_by_name: HashMap<String, Vec<String>>,
+    symbols_by_name: HashMap<(String, String), Vec<String>>,
     files_by_key: HashMap<String, Vec<String>>,
     pending: Vec<PendingRelationship>,
     diagnostics: Vec<Diagnostic>,
@@ -242,6 +242,8 @@ impl ScanState {
         let mut scopes: Vec<Scope> = Vec::new();
         let mut brace_depth = 0_i32;
         let mut rust_raw_end: Option<String> = None;
+        let mut javascript_template_open = false;
+        let mut block_comment_depth = 0_usize;
 
         for (index, raw_line) in content.lines().enumerate() {
             let line_number = index + 1;
@@ -251,7 +253,12 @@ impl ScanState {
                 }
                 continue;
             }
-            let code_line = if language == "rust" {
+            let template_masked;
+            let code_line = if matches!(language, "javascript" | "typescript") {
+                template_masked =
+                    mask_javascript_templates(raw_line, &mut javascript_template_open);
+                template_masked.as_str()
+            } else if language == "rust" {
                 if let Some((start, content_start, delimiter)) = rust_raw_string_start(raw_line) {
                     if !raw_line[content_start..].contains(&delimiter) {
                         rust_raw_end = Some(delimiter);
@@ -263,8 +270,9 @@ impl ScanState {
             } else {
                 raw_line
             };
-            let line = strip_line_comment(code_line, language);
-            let call_line = mask_quoted_strings(line);
+            let block_masked = mask_block_comments(code_line, &mut block_comment_depth);
+            let line = strip_line_comment(&block_masked, language);
+            let call_line = mask_quoted_strings(&line);
             let indent = raw_line.len() - raw_line.trim_start().len();
             if language == "python" && !line.trim().is_empty() {
                 while scopes.last().is_some_and(|scope| scope.indent >= indent) {
@@ -279,9 +287,28 @@ impl ScanState {
                 }
             }
 
-            if let Some(captures) = patterns.class.captures(line)
+            if let Some(pattern) = patterns.enclosing_scope.as_ref()
+                && let Some(name) = pattern
+                    .captures(&line)
+                    .and_then(|captures| captures.name("name"))
+                && let Some(id) = self
+                    .symbols_by_name
+                    .get(&(language.into(), name.as_str().into()))
+                    .and_then(|ids| (ids.len() == 1).then(|| ids[0].clone()))
+                && self.node_kind(&id) == Some(NodeKind::Class)
+            {
+                scopes.push(Scope {
+                    id,
+                    indent,
+                    brace_depth: brace_depth + 1,
+                });
+            }
+
+            let mut type_definition_name = None;
+            if let Some(captures) = patterns.class.captures(&line)
                 && let Some(name) = captures.name("name")
             {
+                type_definition_name = Some(name.as_str().to_owned());
                 let id = self.add_symbol(
                     file_id,
                     path,
@@ -290,10 +317,26 @@ impl ScanState {
                     NodeKind::Class,
                     line_number,
                 );
-                if let Some(base) = captures.name("base") {
+                let mut bases: Vec<String> = patterns
+                    .relationships
+                    .as_ref()
+                    .into_iter()
+                    .flat_map(|pattern| pattern.captures_iter(&line))
+                    .filter_map(|captures| captures.name("names"))
+                    .flat_map(|names| names.as_str().split(','))
+                    .map(str::trim)
+                    .filter(|name| !name.is_empty())
+                    .map(|name| clean_relationship_target(name, language))
+                    .collect();
+                if bases.is_empty()
+                    && let Some(base) = captures.name("base")
+                {
+                    bases.push(clean_target(base.as_str()));
+                }
+                for base in bases {
                     self.pending.push(PendingRelationship {
                         source: id.clone(),
-                        target_name: clean_target(base.as_str()),
+                        target_name: base,
                         kind: EdgeKind::Inherits,
                         language: language.into(),
                         member_call: false,
@@ -310,16 +353,24 @@ impl ScanState {
             }
 
             let mut definition_name = None;
-            if let Some(captures) = patterns.function.captures(line)
-                && let Some(name) = captures.name("name")
-                && !is_keyword(name.as_str())
+            if let Some(name) = patterns.function.iter().find_map(|pattern| {
+                pattern
+                    .captures(&line)
+                    .and_then(|captures| captures.name("name").map(|name| name.as_str().to_owned()))
+            }) && !is_keyword(&name)
             {
-                definition_name = Some(name.as_str().to_owned());
+                definition_name = Some(name.clone());
+                let parent_id = scopes
+                    .iter()
+                    .rev()
+                    .find(|scope| self.node_kind(&scope.id) == Some(NodeKind::Class))
+                    .map(|scope| scope.id.as_str())
+                    .unwrap_or(file_id);
                 let id = self.add_symbol(
-                    file_id,
+                    parent_id,
                     path,
                     language,
-                    name.as_str(),
+                    &name,
                     NodeKind::Function,
                     line_number,
                 );
@@ -337,11 +388,15 @@ impl ScanState {
                 .map(|scope| scope.id.clone())
                 .unwrap_or_else(|| file_id.into());
 
-            for captures in patterns.import.captures_iter(line) {
+            for captures in patterns
+                .import
+                .iter()
+                .flat_map(|pattern| pattern.captures_iter(&line))
+            {
                 if let Some(target) = captures.name("name").or_else(|| captures.name("name2")) {
                     self.pending.push(PendingRelationship {
                         source: file_id.into(),
-                        target_name: clean_target(target.as_str()),
+                        target_name: clean_import_target(target.as_str(), language),
                         kind: EdgeKind::Imports,
                         language: language.into(),
                         member_call: false,
@@ -352,14 +407,25 @@ impl ScanState {
                 }
             }
 
-            for captures in patterns.call.captures_iter(&call_line) {
+            for captures in patterns
+                .call
+                .iter()
+                .flat_map(|pattern| pattern.captures_iter(&call_line))
+            {
                 let Some(target_match) = captures.name("name") else {
                     continue;
                 };
                 let target = target_match.as_str();
                 let prefix = call_line[..target_match.start()].trim_end();
                 let member_call = prefix.ends_with('.') || prefix.ends_with("->");
-                if definition_name.as_deref() != Some(target) && !is_keyword(target) {
+                let definition_call_name = definition_name
+                    .as_deref()
+                    .and_then(|name| name.rsplit('.').next())
+                    .map(|name| name.trim_start_matches('~'));
+                if definition_call_name != Some(target)
+                    && type_definition_name.as_deref() != Some(target)
+                    && !is_keyword(target)
+                {
                     self.pending.push(PendingRelationship {
                         source: source.clone(),
                         target_name: clean_target(target),
@@ -378,7 +444,7 @@ impl ScanState {
 
     fn add_symbol(
         &mut self,
-        file_id: &str,
+        parent_id: &str,
         path: &str,
         language: &str,
         name: &str,
@@ -397,18 +463,18 @@ impl ScanState {
             kind,
             name: name.into(),
             path: Some(path.into()),
-            parent: Some(file_id.into()),
+            parent: Some(parent_id.into()),
             language: Some(language.into()),
             line: Some(line),
             lines_of_code: 0,
             attributes: BTreeMap::new(),
         });
         self.symbols_by_name
-            .entry(name.into())
+            .entry((language.into(), name.into()))
             .or_default()
             .push(id.clone());
         self.add_edge(
-            file_id.into(),
+            parent_id.into(),
             id.clone(),
             EdgeKind::Defines,
             "brick-lexical",
@@ -452,10 +518,13 @@ impl ScanState {
             None
         } else {
             self.symbols_by_name
-                .get(name)
+                .get(&(language.into(), name.into()))
                 .or_else(|| {
                     (!name.contains("::"))
-                        .then(|| self.symbols_by_name.get(leaf_name))
+                        .then(|| {
+                            self.symbols_by_name
+                                .get(&(language.into(), leaf_name.into()))
+                        })
                         .flatten()
                 })
                 .and_then(|ids| (ids.len() == 1).then(|| ids[0].clone()))
@@ -522,8 +591,17 @@ impl ScanState {
         confidence: f64,
         provenance: impl Into<String>,
     ) {
+        let provenance = provenance.into();
         let key = (source.clone(), target.clone(), kind);
         if !self.edge_keys.insert(key) {
+            if let Some(edge) = self
+                .edges
+                .iter_mut()
+                .find(|edge| edge.source == source && edge.target == target && edge.kind == kind)
+                && !edge.evidence.locations.contains(&provenance)
+            {
+                edge.evidence.locations.push(provenance);
+            }
             return;
         }
         let identity = format!("{source}:{}:{target}", edge_kind_name(kind));
@@ -561,55 +639,140 @@ struct Scope {
 
 struct Patterns {
     class: Regex,
-    function: Regex,
-    import: Regex,
-    call: Regex,
+    function: Vec<Regex>,
+    import: Vec<Regex>,
+    call: Vec<Regex>,
+    relationships: Option<Regex>,
+    enclosing_scope: Option<Regex>,
 }
 
 impl Patterns {
     fn new(language: &str) -> Self {
-        let (class, function, import) = match language {
+        let (class, functions, imports, relationships) = match language {
             "python" => (
                 r"^\s*class\s+(?P<name>[A-Za-z_]\w*)(?:\((?P<base>[A-Za-z_][\w.]*)\))?",
-                r"^\s*(?:async\s+)?def\s+(?P<name>[A-Za-z_]\w*)\s*\(",
-                r"^\s*(?:from\s+(?P<name>[A-Za-z_][\w.]*)\s+import|import\s+(?P<name2>[A-Za-z_][\w.]*))",
+                vec![r"^\s*(?:async\s+)?def\s+(?P<name>[A-Za-z_]\w*)\s*\("],
+                vec![
+                    r"^\s*(?:from\s+(?P<name>[A-Za-z_][\w.]*)\s+import|import\s+(?P<name2>[A-Za-z_][\w.]*))",
+                ],
+                None,
             ),
             "rust" => (
                 r"^\s*(?:pub(?:\([^)]*\))?\s+)?(?:struct|enum|trait)\s+(?P<name>[A-Za-z_]\w*)",
-                r"^\s*(?:pub(?:\([^)]*\))?\s+)?(?:async\s+)?fn\s+(?P<name>[A-Za-z_]\w*)\s*(?:<[^>]*>)?\s*\(",
-                r"^\s*use\s+(?P<name>[A-Za-z_][\w:]*)",
+                vec![
+                    r#"^\s*(?:pub(?:\([^)]*\))?\s+)?(?:(?:const|async|unsafe)\s+)*(?:extern(?:\s+"[^"]+")?\s+)?fn\s+(?P<name>[A-Za-z_]\w*)\s*(?:<[^>]*>)?\s*\("#,
+                ],
+                vec![r"^\s*use\s+(?P<name>[A-Za-z_][\w:]*)"],
+                None,
             ),
-            "javascript" | "typescript" => (
-                r"^\s*(?:export\s+)?class\s+(?P<name>[A-Za-z_$][\w$]*)(?:\s+extends\s+(?P<base>[A-Za-z_$][\w$]*))?",
-                r"^\s*(?:export\s+)?(?:async\s+)?function\s+(?P<name>[A-Za-z_$][\w$]*)\s*\(",
-                r#"^\s*import(?:[^'\"]*from\s*)?['\"](?P<name>[^'\"]+)['\"]"#,
+            "c" => (
+                r"^\s*(?:typedef\s+)?(?:struct|union|enum)\s+(?P<name>[A-Za-z_]\w*)",
+                vec![r"^\s*(?:[\w*&]+\s+)+(?P<name>[A-Za-z_]\w*)\s*\([^;{}]*\)\s*\{?\s*$"],
+                vec![r#"^\s*#\s*include\s*[<\"](?P<name>[^>\"]+)[>\"]"#],
+                None,
+            ),
+            "cpp" => (
+                r"^\s*(?:class|struct|union|enum(?:\s+class)?)\s+(?P<name>[A-Za-z_]\w*)(?:\s+final)?",
+                vec![
+                    r"^\s*(?:[\w:<>,*&]+\s+)+(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\([^;{}]*\)\s*(?:const\s*)?(?:noexcept\s*)?(?:(?:override|final)\s*)*(?:\{|=\s*(?:default|delete)\s*;)?\s*$",
+                    r"^\s*(?P<name>~?[A-Za-z_]\w*)\s*\([^;{}]*\)\s*(?::[^{}]*)?\s*(?:noexcept\s*)?(?:\{\s*\}|\{|=\s*(?:default|delete)\s*;)\s*$",
+                    r"^\s*(?:[\w:<>,*&]+\s+)+(?P<name>operator\s*(?:[^\s(]+|\(\)))\s*\([^;{}]*\)\s*(?:const\s*)?(?:noexcept\s*)?(?:\{|=\s*(?:default|delete)\s*;)\s*$",
+                ],
+                vec![r#"^\s*#\s*include\s*[<\"](?P<name>[^>\"]+)[>\"]"#],
+                Some(r":\s*(?P<names>[^\{]+)"),
+            ),
+            "javascript" => (
+                r"^\s*(?:export\s+)?(?:default\s+)?class\s+(?P<name>[A-Za-z_$][\w$]*)(?:\s+extends\s+(?P<base>[A-Za-z_$][\w$]*))?",
+                vec![
+                    r"^\s*(?:export\s+)?(?:default\s+)?(?:async\s+)?function\s+(?P<name>[A-Za-z_$][\w$]*)\s*\(",
+                    r"^\s*(?:(?:static|async|get|set)\s+)*(?P<name>constructor|[A-Za-z_$][\w$]*)\s*\([^)]*\)\s*\{",
+                    r"^\s*(?:export\s+)?(?:const|let|var)\s+(?P<name>[A-Za-z_$][\w$]*)\s*=\s*(?:async\s*)?(?:\([^)]*\)|[A-Za-z_$][\w$]*)\s*=>",
+                ],
+                javascript_import_patterns(),
+                Some(r"\bextends\s+(?P<names>[A-Za-z_$][\w$]*)"),
+            ),
+            "typescript" => (
+                r"^\s*(?:export\s+)?(?:default\s+)?(?:(?:abstract|declare)\s+)?(?:class|interface|enum|namespace)\s+(?P<name>[A-Za-z_$][\w$]*)(?:\s*<[^>{}]+>)?",
+                vec![
+                    r"^\s*(?:export\s+)?(?:default\s+)?(?:async\s+)?function\s+(?P<name>[A-Za-z_$][\w$]*)\s*(?:<[^>{}]+>)?\s*\(",
+                    r"^\s*(?:(?:public|protected|private|static|abstract|async|get|set|readonly|override)\s+)*(?P<name>constructor|[A-Za-z_$][\w$]*)\s*(?:<[^>{}]+>)?\s*\([^)]*\)\s*(?::[^;{]+)?\s*\{",
+                    r"^\s*(?:export\s+)?(?:const|let|var)\s+(?P<name>[A-Za-z_$][\w$]*)\s*(?::[^=]+)?=\s*(?:async\s*)?(?:<[^>{}]+>\s*)?(?:\([^)]*\)|[A-Za-z_$][\w$]*)\s*(?::[^=]+)?=>",
+                ],
+                javascript_import_patterns(),
+                Some(
+                    r"\b(?:extends|implements)\s+(?P<names>[A-Za-z_$][\w$]*(?:<[^>{}]+>)?(?:\s*,\s*[A-Za-z_$][\w$]*(?:<[^>{}]+>)?)*)",
+                ),
             ),
             "dart" => (
                 r"^\s*(?:(?:abstract|base|final|interface|sealed)\s+)?(?:class|mixin|enum|extension(?:\s+type)?)\s+(?P<name>[A-Za-z_]\w*)(?:\s+extends\s+(?P<base>[A-Za-z_]\w*))?",
-                r"^\s*(?:(?:external|static|abstract|covariant|late)\s+)*(?:(?:[A-Za-z_]\w*(?:<[^>{};()]+>)?[?!]?)\s+)?(?P<name>[A-Za-z_]\w*)\s*\([^;{}]*\)\s*(?:(?:async|sync)\*?\s*)?(?:\{|=>)",
-                r#"^\s*import\s+['\"](?P<name>[^'\"]+)['\"]"#,
+                vec![
+                    r"^\s*(?:(?:external|static|abstract|covariant|late)\s+)*(?:(?:[A-Za-z_]\w*(?:<[^>{};()]+>)?[?!]?)\s+)?(?P<name>[A-Za-z_]\w*)\s*\([^;{}]*\)\s*(?:(?:async|sync)\*?\s*)?(?:\{|=>)",
+                    r"^\s*(?P<name>[A-Za-z_]\w*\.[A-Za-z_]\w*)\s*\([^;{}]*\)\s*(?:(?:async|sync)\*?\s*)?(?:\{|=>|;)",
+                    r"^\s*(?:(?:external|static|abstract|covariant|late)\s+)*(?:(?:[A-Za-z_]\w*(?:<[^>{};()]+>)?[?!]?)\s+)?get\s+(?P<name>[A-Za-z_]\w*)\s*(?:=>|\{)",
+                    r"^\s*(?:(?:external|static|abstract|covariant|late)\s+)*set\s+(?P<name>[A-Za-z_]\w*)\s*\([^;{}]*\)\s*(?:=>|\{|;)",
+                ],
+                vec![r#"^\s*(?:import|export|part)\s+['\"](?P<name>[^'\"]+)['\"]"#],
+                Some(
+                    r"\b(?:extends|with|implements|on)\s+(?P<names>[A-Za-z_]\w*(?:\s*,\s*[A-Za-z_]\w*)*)",
+                ),
             ),
             _ => (
                 r"^\s*(?:class|struct)\s+(?P<name>[A-Za-z_]\w*)(?:\s*:\s*(?:public\s+|protected\s+|private\s+)?(?P<base>[A-Za-z_:]\w*(?:::\w+)*))?",
-                r"^\s*(?:[\w:<>,*&]+\s+)+(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\([^;{}]*\)\s*(?:const\s*)?(?:noexcept\s*)?\{?\s*$",
-                r#"^\s*#\s*include\s*[<\"](?P<name>[^>\"]+)[>\"]"#,
+                vec![
+                    r"^\s*(?:[\w:<>,*&]+\s+)+(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\([^;{}]*\)\s*(?:const\s*)?(?:noexcept\s*)?\{?\s*$",
+                ],
+                vec![r#"^\s*#\s*include\s*[<\"](?P<name>[^>\"]+)[>\"]"#],
+                None,
             ),
         };
+        let mut calls = vec![r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\("];
+        if language == "rust" {
+            calls.extend([
+                r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*::\s*<[^>]+>\s*\(",
+                r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)!\s*\(",
+            ]);
+        }
         Self {
             class: Regex::new(class).expect("class regex is static"),
-            function: Regex::new(function).expect("function regex is static"),
-            import: Regex::new(import).expect("import regex is static"),
-            call: Regex::new(r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\(")
-                .expect("call regex is static"),
+            function: functions
+                .into_iter()
+                .map(|pattern| Regex::new(pattern).expect("function regex is static"))
+                .collect(),
+            import: imports
+                .into_iter()
+                .map(|pattern| Regex::new(pattern).expect("import regex is static"))
+                .collect(),
+            call: calls
+                .into_iter()
+                .map(|pattern| Regex::new(pattern).expect("call regex is static"))
+                .collect(),
+            relationships: relationships
+                .map(|pattern| Regex::new(pattern).expect("relationship regex is static")),
+            enclosing_scope: (language == "rust").then(|| {
+                Regex::new(
+                    r"^\s*impl(?:<[^>]*>)?\s+(?:(?:[A-Za-z_]\w*(?:::\w+)*)\s+for\s+)?(?P<name>[A-Za-z_]\w*)",
+                )
+                .expect("scope regex is static")
+            }),
         }
     }
 }
 
+fn javascript_import_patterns() -> Vec<&'static str> {
+    vec![
+        r#"^\s*import(?:\s+type)?(?:[^'\"]*from\s*)?['\"](?P<name>[^'\"]+)['\"]"#,
+        r#"^\s*export(?:\s+type)?\s+[^'\"]*from\s*['\"](?P<name>[^'\"]+)['\"]"#,
+        r#"\brequire\s*\(\s*['\"](?P<name>[^'\"]+)['\"]\s*\)"#,
+        r#"\bimport\s*\(\s*['\"](?P<name>[^'\"]+)['\"]\s*\)"#,
+    ]
+}
+
 fn language_for(path: &Path) -> Option<&'static str> {
     match path.extension()?.to_str()? {
         "rs" => Some("rust"),
         "py" => Some("python"),
-        "c" | "h" | "cc" | "cpp" | "cxx" | "hh" | "hpp" | "hxx" => Some("cpp"),
+        "c" => Some("c"),
+        "h" | "cc" | "cpp" | "cxx" | "hh" | "hpp" | "hxx" => Some("cpp"),
         "js" | "jsx" | "mjs" | "cjs" => Some("javascript"),
         "ts" | "tsx" | "mts" | "cts" => Some("typescript"),
         "swift" => Some("swift"),
@@ -618,13 +781,93 @@ fn language_for(path: &Path) -> Option<&'static str> {
     }
 }
 
-fn strip_line_comment<'a>(line: &'a str, language: &str) -> &'a str {
-    let marker = if language == "python" { '#' } else { '/' };
-    if marker == '/' {
-        line.split_once("//").map_or(line, |(before, _)| before)
-    } else {
-        line.split_once('#').map_or(line, |(before, _)| before)
+fn strip_line_comment(line: &str, language: &str) -> String {
+    let chars: Vec<_> = line.chars().collect();
+    let mut quote = None;
+    let mut escaped = false;
+    let mut index = 0;
+    while index < chars.len() {
+        let ch = chars[index];
+        if let Some(active_quote) = quote {
+            if escaped {
+                escaped = false;
+            } else if ch == '\\' {
+                escaped = true;
+            } else if ch == active_quote {
+                quote = None;
+            }
+        } else if matches!(ch, '\'' | '"') && has_closing_quote(&chars, index + 1, ch) {
+            quote = Some(ch);
+        } else if language == "python" && ch == '#'
+            || language != "python" && ch == '/' && chars.get(index + 1) == Some(&'/')
+        {
+            return chars[..index].iter().collect();
+        }
+        index += 1;
     }
+    line.into()
+}
+
+fn mask_block_comments(line: &str, depth: &mut usize) -> String {
+    let chars: Vec<_> = line.chars().collect();
+    let mut result = String::with_capacity(line.len());
+    let mut quote = None;
+    let mut escaped = false;
+    let mut index = 0;
+    while index < chars.len() {
+        let ch = chars[index];
+        let next = chars.get(index + 1).copied();
+        if *depth > 0 {
+            if ch == '/' && next == Some('*') {
+                *depth += 1;
+                result.push_str("  ");
+                index += 2;
+            } else if ch == '*' && next == Some('/') {
+                *depth -= 1;
+                result.push_str("  ");
+                index += 2;
+            } else {
+                result.push(' ');
+                index += 1;
+            }
+        } else if let Some(active_quote) = quote {
+            result.push(ch);
+            if escaped {
+                escaped = false;
+            } else if ch == '\\' {
+                escaped = true;
+            } else if ch == active_quote {
+                quote = None;
+            }
+            index += 1;
+        } else if matches!(ch, '\'' | '"') && has_closing_quote(&chars, index + 1, ch) {
+            quote = Some(ch);
+            result.push(ch);
+            index += 1;
+        } else if ch == '/' && next == Some('*') {
+            *depth = 1;
+            result.push_str("  ");
+            index += 2;
+        } else {
+            result.push(ch);
+            index += 1;
+        }
+    }
+    result
+}
+
+fn has_closing_quote(chars: &[char], start: usize, quote: char) -> bool {
+    let mut escaped = false;
+    for ch in &chars[start..] {
+        if escaped {
+            escaped = false;
+        } else if *ch == '\\' {
+            escaped = true;
+        } else if *ch == quote {
+            return true;
+        }
+    }
+    false
 }
 
 fn brace_delta(line: &str) -> i32 {
@@ -659,6 +902,29 @@ fn mask_quoted_strings(line: &str) -> String {
     result
 }
 
+fn mask_javascript_templates(line: &str, open: &mut bool) -> String {
+    let mut result = String::with_capacity(line.len());
+    let mut escaped = false;
+    for ch in line.chars() {
+        if *open {
+            if escaped {
+                escaped = false;
+            } else if ch == '\\' {
+                escaped = true;
+            } else if ch == '`' {
+                *open = false;
+            }
+            result.push(' ');
+        } else if ch == '`' {
+            *open = true;
+            result.push(' ');
+        } else {
+            result.push(ch);
+        }
+    }
+    result
+}
+
 fn rust_raw_string_start(line: &str) -> Option<(usize, usize, String)> {
     let bytes = line.as_bytes();
     for start in 0..bytes.len() {
@@ -687,6 +953,30 @@ fn clean_target(value: &str) -> String {
         .into()
 }
 
+fn clean_import_target(value: &str, language: &str) -> String {
+    let target = clean_target(value);
+    if language == "rust" {
+        target.trim_end_matches("::").into()
+    } else {
+        target
+    }
+}
+
+fn clean_relationship_target(value: &str, language: &str) -> String {
+    let target = clean_target(value);
+    if language == "cpp" {
+        target
+            .split_whitespace()
+            .filter(|part| !matches!(*part, "public" | "protected" | "private" | "virtual"))
+            .collect::<Vec<_>>()
+            .join(" ")
+    } else if matches!(language, "javascript" | "typescript") {
+        target.split('<').next().unwrap_or(&target).trim().into()
+    } else {
+        target
+    }
+}
+
 fn import_keys(name: &str, language: &str) -> Vec<String> {
     let mut keys = vec![name.to_owned()];
     match language {
@@ -747,15 +1037,39 @@ fn is_keyword(name: &str) -> bool {
             | "assert"
             | "assert_eq"
             | "println"
+            | "import"
+            | "require"
     )
 }
 
 #[cfg(test)]
 mod tests {
-    use super::{ScanOptions, scan, scan_with_options};
+    use super::{ScanOptions, mask_block_comments, scan, scan_with_options, strip_line_comment};
     use crate::model::{EdgeKind, NodeKind};
     use std::fs;
 
+    #[test]
+    fn masks_nested_block_comments_without_truncating_quoted_urls() {
+        let mut depth = 0;
+        assert_eq!(
+            strip_line_comment(
+                r#"import value from "https://example.invalid/value.js"; // trailing"#,
+                "javascript"
+            ),
+            r#"import value from "https://example.invalid/value.js"; "#
+        );
+        assert_eq!(
+            mask_block_comments("code /* outer", &mut depth),
+            "code         "
+        );
+        assert_eq!(depth, 1);
+        let nested = "/* inner */ end */";
+        let masked = mask_block_comments(nested, &mut depth);
+        assert_eq!(masked.len(), nested.len());
+        assert!(masked.trim().is_empty());
+        assert_eq!(depth, 0);
+    }
+
     #[test]
     fn scans_functions_calls_and_cycles() {
         let dir = tempfile::tempdir().unwrap();
@@ -953,6 +1267,137 @@ mod tests {
         );
     }
 
+    #[test]
+    fn does_not_resolve_calls_across_language_boundaries() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::write(dir.path().join("library.rs"), "fn shared() {}\n").unwrap();
+        fs::write(
+            dir.path().join("application.js"),
+            "function local() {}\nfunction caller() { local(); shared(); }\n",
+        )
+        .unwrap();
+
+        let building = scan(dir.path()).unwrap();
+        let caller = building
+            .nodes
+            .iter()
+            .find(|node| node.language.as_deref() == Some("javascript") && node.name == "caller")
+            .unwrap();
+        let javascript_local = building
+            .nodes
+            .iter()
+            .find(|node| node.language.as_deref() == Some("javascript") && node.name == "local")
+            .unwrap();
+        let rust_shared = building
+            .nodes
+            .iter()
+            .find(|node| node.language.as_deref() == Some("rust") && node.name == "shared")
+            .unwrap();
+        let caller_edges: Vec<_> = building
+            .edges
+            .iter()
+            .filter(|edge| edge.kind == EdgeKind::Calls && edge.source == caller.id)
+            .collect();
+
+        assert!(
+            caller_edges
+                .iter()
+                .any(|edge| edge.target == javascript_local.id)
+        );
+        assert!(
+            !caller_edges
+                .iter()
+                .any(|edge| edge.target == rust_shared.id)
+        );
+        assert!(caller_edges.iter().any(|edge| {
+            building.nodes.iter().any(|node| {
+                node.id == edge.target && node.kind == NodeKind::External && node.name == "shared"
+            })
+        }));
+    }
+
+    #[test]
+    fn parents_recognized_methods_to_their_enclosing_type() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::write(
+            dir.path().join("worker.dart"),
+            "class Worker {\n  void execute() {}\n}\n",
+        )
+        .unwrap();
+
+        let building = scan(dir.path()).unwrap();
+        let worker = building
+            .nodes
+            .iter()
+            .find(|node| node.kind == NodeKind::Class && node.name == "Worker")
+            .unwrap();
+        let execute = building
+            .nodes
+            .iter()
+            .find(|node| node.kind == NodeKind::Function && node.name == "execute")
+            .unwrap();
+
+        assert_eq!(execute.parent.as_deref(), Some(worker.id.as_str()));
+        assert!(building.edges.iter().any(|edge| {
+            edge.kind == EdgeKind::Defines && edge.source == worker.id && edge.target == execute.id
+        }));
+    }
+
+    #[test]
+    fn does_not_promote_python_type_declarations_to_calls() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::write(
+            dir.path().join("worker.py"),
+            "class Base:\n    pass\nclass Worker(Base):\n    pass\n",
+        )
+        .unwrap();
+
+        let building = scan(dir.path()).unwrap();
+        assert!(building.edges.iter().all(|edge| {
+            edge.kind != EdgeKind::Calls
+                || !building
+                    .nodes
+                    .iter()
+                    .any(|node| node.id == edge.target && node.name == "Worker")
+        }));
+    }
+
+    #[test]
+    fn retains_every_location_for_a_deduplicated_dependency_edge() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::write(
+            dir.path().join("calls.rs"),
+            "fn helper() {}\nfn caller() {\n  helper();\n  helper();\n}\n",
+        )
+        .unwrap();
+
+        let building = scan(dir.path()).unwrap();
+        let caller = building
+            .nodes
+            .iter()
+            .find(|node| node.kind == NodeKind::Function && node.name == "caller")
+            .unwrap();
+        let helper = building
+            .nodes
+            .iter()
+            .find(|node| node.kind == NodeKind::Function && node.name == "helper")
+            .unwrap();
+        let call = building
+            .edges
+            .iter()
+            .find(|edge| {
+                edge.kind == EdgeKind::Calls && edge.source == caller.id && edge.target == helper.id
+            })
+            .unwrap();
+        let serialized = serde_json::to_value(&call.evidence).unwrap();
+
+        assert_eq!(call.evidence.provenance, "calls.rs:3");
+        assert_eq!(
+            serialized["locations"],
+            serde_json::json!(["calls.rs:3", "calls.rs:4"])
+        );
+    }
+
     #[test]
     fn scans_dart_structure_without_promoting_control_flow_or_strings() {
         let dir = tempfile::tempdir().unwrap();
diff --git a/tests/benchmarks/README.md b/tests/benchmarks/README.md
index fa4087f..bf6db65 100644
--- a/tests/benchmarks/README.md
+++ b/tests/benchmarks/README.md
@@ -5,6 +5,7 @@ xplan and Fold's optimization harness.
 
     python3 tests/benchmarks/runner.py self-test
     python3 tests/benchmarks/runner.py run lexical_smoke
+    python3 tests/benchmarks/runner.py run language_parity
     python3 tests/benchmarks/runner.py run yams_architecture --corpus /path/to/yams
 
 Each run writes a resolved plan, per-repeat graph/HTML artifacts, summary JSON,
@@ -13,6 +14,11 @@ across repeats. The seed corpus has explicit positive cycle and relationship
 expectations; it is not representative enough for performance or language-wide
 precision claims.
 
+The `language_parity` plan repeats the labeled language corpus three times,
+requires stable graph identities, and gates minimum file and symbol evidence for
+each advertised language independently. Python and Swift counts characterize
+their secondary tier; they do not promote those profiles.
+
 The `yams_architecture` plan is a real-corpus integration benchmark. It records
 three stable-identity scans and excludes YAMS's checked-in `site` output with
 Brick's explicit `--exclude` option. Validate each resulting graph with YAMS's
diff --git a/tests/benchmarks/plans/language_parity.json b/tests/benchmarks/plans/language_parity.json
new file mode 100644
index 0000000..c586f3b
--- /dev/null
+++ b/tests/benchmarks/plans/language_parity.json
@@ -0,0 +1,31 @@
+{
+  "schema_version": 1,
+  "name": "language_parity",
+  "corpus": "tests/fixtures/languages",
+  "repeats": 3,
+  "expect": {
+    "min_symbols": 35,
+    "min_dependency_edges": 35,
+    "max_cycles": 2,
+    "language_min_symbols": {
+      "dart": 7,
+      "rust": 8,
+      "c": 5,
+      "cpp": 8,
+      "javascript": 8,
+      "typescript": 9,
+      "python": 4,
+      "swift": 2
+    },
+    "language_min_files": {
+      "dart": 1,
+      "rust": 2,
+      "c": 1,
+      "cpp": 1,
+      "javascript": 5,
+      "typescript": 3,
+      "python": 2,
+      "swift": 1
+    }
+  }
+}
diff --git a/tests/benchmarks/runner.py b/tests/benchmarks/runner.py
index 44f6ba9..edaa050 100755
--- a/tests/benchmarks/runner.py
+++ b/tests/benchmarks/runner.py
@@ -131,7 +131,9 @@ def command_for(
     ]
 
 
-def fixture_assertions(metrics: dict, expected: dict) -> dict[str, bool]:
+def fixture_assertions(
+    metrics: dict, expected: dict, model: dict | None = None
+) -> dict[str, bool]:
     assertions = {
         "symbols": metrics["symbol_count"] >= expected["min_symbols"],
         "dependencies": metrics["dependency_edge_count"]
@@ -141,6 +143,24 @@ def fixture_assertions(metrics: dict, expected: dict) -> dict[str, bool]:
         assertions["cycles"] = metrics["cycle_count"] == expected["cycles"]
     if "max_cycles" in expected:
         assertions["max_cycles"] = metrics["cycle_count"] <= expected["max_cycles"]
+    nodes = [] if model is None else model.get("nodes", [])
+    for language, minimum in expected.get("language_min_symbols", {}).items():
+        assertions[f"{language}_symbols"] = (
+            sum(
+                node.get("language") == language
+                and node.get("kind") in {"class", "function"}
+                for node in nodes
+            )
+            >= minimum
+        )
+    for language, minimum in expected.get("language_min_files", {}).items():
+        assertions[f"{language}_files"] = (
+            sum(
+                node.get("language") == language and node.get("kind") == "file"
+                for node in nodes
+            )
+            >= minimum
+        )
     return assertions
 
 
@@ -215,7 +235,7 @@ def run_plan(
 
     metrics = samples[0]["metrics"]
     expected = plan["expect"]
-    assertions = fixture_assertions(metrics, expected)
+    assertions = fixture_assertions(metrics, expected, model)
     if not all(assertions.values()):
         raise AssertionError(f"fixture expectations failed: {assertions}; metrics={metrics}")
 
diff --git a/tests/benchmarks/test_runner.py b/tests/benchmarks/test_runner.py
index 843d5a4..77017c4 100644
--- a/tests/benchmarks/test_runner.py
+++ b/tests/benchmarks/test_runner.py
@@ -77,6 +77,32 @@ class RunnerTests(unittest.TestCase):
             {"symbols": True, "dependencies": True, "max_cycles": True},
         )
 
+    def test_language_expectations_cannot_be_satisfied_by_another_language(self) -> None:
+        metrics = {"symbol_count": 3, "dependency_edge_count": 2, "cycle_count": 0}
+        expected = {
+            "min_symbols": 2,
+            "min_dependency_edges": 1,
+            "cycles": 0,
+            "language_min_symbols": {"dart": 2, "rust": 2},
+            "language_min_files": {"dart": 1, "rust": 1},
+        }
+        model = {
+            "nodes": [
+                {"kind": "file", "language": "dart"},
+                {"kind": "class", "language": "dart"},
+                {"kind": "function", "language": "dart"},
+                {"kind": "file", "language": "rust"},
+                {"kind": "function", "language": "rust"},
+            ]
+        }
+
+        assertions = runner.fixture_assertions(metrics, expected, model)
+
+        self.assertTrue(assertions["dart_symbols"])
+        self.assertTrue(assertions["dart_files"])
+        self.assertFalse(assertions["rust_symbols"])
+        self.assertTrue(assertions["rust_files"])
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/fixtures/languages/c/basic.c b/tests/fixtures/languages/c/basic.c
new file mode 100644
index 0000000..097d077
--- /dev/null
+++ b/tests/fixtures/languages/c/basic.c
@@ -0,0 +1,27 @@
+#include "support.h"
+
+struct Worker {
+    int state;
+};
+
+union Payload {
+    int integer;
+    double decimal;
+};
+
+enum State {
+    ready
+};
+
+int start() {
+    return helper();
+}
+
+int helper() {
+    return 0;
+}
+
+/*
+struct CommentGhost {};
+int comment_call() { return phantom_call(); }
+*/
diff --git a/tests/fixtures/languages/cpp/basic.cpp b/tests/fixtures/languages/cpp/basic.cpp
new file mode 100644
index 0000000..683d0cc
--- /dev/null
+++ b/tests/fixtures/languages/cpp/basic.cpp
@@ -0,0 +1,26 @@
+#include "support.hpp"
+
+class Base {};
+class Runnable {};
+
+template <typename T>
+class Worker final : public Base, private Runnable {
+public:
+    Worker() {}
+    ~Worker() {}
+
+    void start() override {
+        helper();
+    }
+
+    Worker& operator=(const Worker&) = default;
+};
+
+int helper() {
+    return 0;
+}
+
+/*
+class CommentGhost {};
+int comment_call() { return phantom_call(); }
+*/
diff --git a/tests/fixtures/languages/dart/basic.dart b/tests/fixtures/languages/dart/basic.dart
new file mode 100644
index 0000000..36a9695
--- /dev/null
+++ b/tests/fixtures/languages/dart/basic.dart
@@ -0,0 +1,24 @@
+import 'package:example/base.dart';
+export 'package:example/public.dart';
+part 'generated.dart';
+
+mixin Logging {}
+
+abstract class Controller extends Base with Logging implements Runnable {
+  Controller.named();
+
+  String get label => 'controller';
+
+  set label(String value) {}
+
+  void start() {
+    helper();
+  }
+
+  void helper() {}
+}
+
+/*
+class CommentGhost {}
+void commentCall() { phantomCall(); }
+*/
diff --git a/tests/fixtures/languages/javascript/api.js b/tests/fixtures/languages/javascript/api.js
new file mode 100644
index 0000000..e9c0441
--- /dev/null
+++ b/tests/fixtures/languages/javascript/api.js
@@ -0,0 +1 @@
+export function api() {}
diff --git a/tests/fixtures/languages/javascript/base.js b/tests/fixtures/languages/javascript/base.js
new file mode 100644
index 0000000..421591a
--- /dev/null
+++ b/tests/fixtures/languages/javascript/base.js
@@ -0,0 +1 @@
+export class Base {}
diff --git a/tests/fixtures/languages/javascript/basic.js b/tests/fixtures/languages/javascript/basic.js
new file mode 100644
index 0000000..b02cf45
--- /dev/null
+++ b/tests/fixtures/languages/javascript/basic.js
@@ -0,0 +1,27 @@
+import { Base } from './base.js';
+export { api } from './api.js';
+
+const legacy = require('./legacy.cjs');
+const lazy = import('./lazy.js');
+
+export default class Worker extends Base {
+  constructor() {}
+
+  start() {
+    helper();
+  }
+}
+
+const arrow = () => helper();
+
+function helper() {}
+
+const ignored = `
+class Phantom extends Ghost {}
+function fake() { phantomCall(); }
+`;
+
+/*
+class CommentGhost {}
+function commentCall() { phantomCall(); }
+*/
diff --git a/tests/fixtures/languages/javascript/lazy.js b/tests/fixtures/languages/javascript/lazy.js
new file mode 100644
index 0000000..603a6d6
--- /dev/null
+++ b/tests/fixtures/languages/javascript/lazy.js
@@ -0,0 +1 @@
+export function lazy() {}
diff --git a/tests/fixtures/languages/javascript/legacy.cjs b/tests/fixtures/languages/javascript/legacy.cjs
new file mode 100644
index 0000000..f053ebf
--- /dev/null
+++ b/tests/fixtures/languages/javascript/legacy.cjs
@@ -0,0 +1 @@
+module.exports = {};
diff --git a/tests/fixtures/languages/python/base.py b/tests/fixtures/languages/python/base.py
new file mode 100644
index 0000000..764e53e
--- /dev/null
+++ b/tests/fixtures/languages/python/base.py
@@ -0,0 +1,2 @@
+class Base:
+    pass
diff --git a/tests/fixtures/languages/python/basic.py b/tests/fixtures/languages/python/basic.py
new file mode 100644
index 0000000..d83d0ac
--- /dev/null
+++ b/tests/fixtures/languages/python/basic.py
@@ -0,0 +1,10 @@
+from base import Base
+
+
+class Worker(Base):
+    async def start(self):
+        helper()
+
+
+def helper():
+    pass
diff --git a/tests/fixtures/languages/rust/basic.rs b/tests/fixtures/languages/rust/basic.rs
new file mode 100644
index 0000000..f460f8e
--- /dev/null
+++ b/tests/fixtures/languages/rust/basic.rs
@@ -0,0 +1,28 @@
+mod support;
+
+use crate::support::{helper, Dependency};
+
+pub struct Worker;
+
+impl Worker {
+    pub fn start() {
+        helper();
+        generic::<usize>();
+        trace!();
+    }
+}
+
+fn generic<T>() {}
+
+pub const fn constant() -> usize {
+    1
+}
+
+pub unsafe fn unsafe_op() {}
+
+pub extern "C" fn ffi_entry() {}
+
+/*
+struct CommentGhost;
+fn comment_call() { phantom_call(); }
+*/
diff --git a/tests/fixtures/languages/rust/support.rs b/tests/fixtures/languages/rust/support.rs
new file mode 100644
index 0000000..b91c795
--- /dev/null
+++ b/tests/fixtures/languages/rust/support.rs
@@ -0,0 +1,3 @@
+pub struct Dependency;
+
+pub fn helper() {}
diff --git a/tests/fixtures/languages/swift/basic.swift b/tests/fixtures/languages/swift/basic.swift
new file mode 100644
index 0000000..6180272
--- /dev/null
+++ b/tests/fixtures/languages/swift/basic.swift
@@ -0,0 +1,9 @@
+import Foundation
+
+protocol Runnable {}
+
+class Worker: Base {
+    func start() {
+        helper()
+    }
+}
diff --git a/tests/fixtures/languages/typescript/base.ts b/tests/fixtures/languages/typescript/base.ts
new file mode 100644
index 0000000..338e7ef
--- /dev/null
+++ b/tests/fixtures/languages/typescript/base.ts
@@ -0,0 +1 @@
+export class Base<T> {}
diff --git a/tests/fixtures/languages/typescript/basic.ts b/tests/fixtures/languages/typescript/basic.ts
new file mode 100644
index 0000000..4fd6ce1
--- /dev/null
+++ b/tests/fixtures/languages/typescript/basic.ts
@@ -0,0 +1,32 @@
+import type { Base } from './base.js';
+export type { Contract } from './contract.js';
+
+interface Runnable {
+  run<T>(value: T): void;
+}
+
+export abstract class Worker<T> extends Base<T> implements Runnable {
+  constructor() {}
+
+  run<U>(value: U): void {
+    helper();
+  }
+}
+
+const arrow = <T>(value: T): T => identity(value);
+
+function identity<T>(value: T): T {
+  return value;
+}
+
+function helper(): void {}
+
+const ignored = `
+interface Phantom {}
+function fake(): void { phantomCall(); }
+`;
+
+/*
+interface CommentGhost {}
+function commentCall(): void { phantomCall(); }
+*/
diff --git a/tests/fixtures/languages/typescript/contract.ts b/tests/fixtures/languages/typescript/contract.ts
new file mode 100644
index 0000000..3a68456
--- /dev/null
+++ b/tests/fixtures/languages/typescript/contract.ts
@@ -0,0 +1 @@
+export interface Contract {}
diff --git a/tests/language_parity.rs b/tests/language_parity.rs
new file mode 100644
index 0000000..ca0d5bd
--- /dev/null
+++ b/tests/language_parity.rs
@@ -0,0 +1,291 @@
+use brick::model::{EdgeKind, NodeKind};
+use brick::scan::scan;
+use std::path::PathBuf;
+
+struct FixtureCase {
+    directory: &'static str,
+    language: &'static str,
+    classes: &'static [&'static str],
+    functions: &'static [&'static str],
+    imports: usize,
+    inherits: usize,
+    calls: usize,
+}
+
+#[test]
+fn first_class_language_fixtures_have_stable_baseline_evidence() {
+    let cases = [
+        FixtureCase {
+            directory: "dart",
+            language: "dart",
+            classes: &["Controller", "Logging"],
+            functions: &["Controller.named", "helper", "label", "label", "start"],
+            imports: 3,
+            inherits: 3,
+            calls: 1,
+        },
+        FixtureCase {
+            directory: "rust",
+            language: "rust",
+            classes: &["Dependency", "Worker"],
+            functions: &[
+                "constant",
+                "ffi_entry",
+                "generic",
+                "helper",
+                "start",
+                "unsafe_op",
+            ],
+            imports: 1,
+            inherits: 0,
+            calls: 3,
+        },
+        FixtureCase {
+            directory: "c",
+            language: "c",
+            classes: &["Payload", "State", "Worker"],
+            functions: &["helper", "start"],
+            imports: 1,
+            inherits: 0,
+            calls: 1,
+        },
+        FixtureCase {
+            directory: "cpp",
+            language: "cpp",
+            classes: &["Base", "Runnable", "Worker"],
+            functions: &["Worker", "helper", "operator=", "start", "~Worker"],
+            imports: 1,
+            inherits: 2,
+            calls: 1,
+        },
+        FixtureCase {
+            directory: "javascript",
+            language: "javascript",
+            classes: &["Base", "Worker"],
+            functions: &["api", "arrow", "constructor", "helper", "lazy", "start"],
+            imports: 4,
+            inherits: 1,
+            calls: 2,
+        },
+        FixtureCase {
+            directory: "typescript",
+            language: "typescript",
+            classes: &["Base", "Contract", "Runnable", "Worker"],
+            functions: &["arrow", "constructor", "helper", "identity", "run"],
+            imports: 2,
+            inherits: 2,
+            calls: 2,
+        },
+    ];
+
+    for case in cases {
+        assert_fixture(case);
+    }
+}
+
+#[test]
+fn rust_fixture_models_impl_ownership_and_local_imports() {
+    let root = fixture_root("rust");
+    let building = scan(&root).unwrap();
+    let worker = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::Class && node.name == "Worker")
+        .unwrap();
+    let start = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::Function && node.name == "start")
+        .unwrap();
+    let support = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::File && node.path.as_deref() == Some("support.rs"))
+        .unwrap();
+
+    assert_eq!(start.parent.as_deref(), Some(worker.id.as_str()));
+    assert!(
+        building
+            .edges
+            .iter()
+            .any(|edge| { edge.kind == EdgeKind::Imports && edge.target == support.id })
+    );
+}
+
+#[test]
+fn cpp_fixture_models_member_ownership_without_declaration_calls() {
+    let root = fixture_root("cpp");
+    let building = scan(&root).unwrap();
+    let worker = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::Class && node.name == "Worker")
+        .unwrap();
+    let members: Vec<_> = building
+        .nodes
+        .iter()
+        .filter(|node| node.kind == NodeKind::Function && node.parent.as_ref() == Some(&worker.id))
+        .map(|node| node.name.as_str())
+        .collect();
+
+    assert_eq!(members.len(), 4);
+    assert!(building.edges.iter().all(|edge| {
+        edge.kind != EdgeKind::Calls
+            || !building.nodes.iter().any(|node| {
+                node.id == edge.target
+                    && matches!(
+                        node.name.as_str(),
+                        "Worker" | "~Worker" | "operator=" | "start"
+                    )
+            })
+    }));
+}
+
+#[test]
+fn javascript_and_typescript_model_members_without_template_phantoms() {
+    for directory in ["javascript", "typescript"] {
+        let building = scan(&fixture_root(directory)).unwrap();
+        let worker = building
+            .nodes
+            .iter()
+            .find(|node| node.kind == NodeKind::Class && node.name == "Worker")
+            .unwrap();
+        let member_names: Vec<_> = building
+            .nodes
+            .iter()
+            .filter(|node| {
+                node.kind == NodeKind::Function && node.parent.as_ref() == Some(&worker.id)
+            })
+            .map(|node| node.name.as_str())
+            .collect();
+
+        assert_eq!(member_names.len(), 2, "{directory} member ownership");
+        assert!(member_names.contains(&"constructor"));
+        assert!(
+            !building
+                .nodes
+                .iter()
+                .any(|node| { matches!(node.name.as_str(), "Phantom" | "fake" | "phantomCall") })
+        );
+        assert!(
+            building
+                .edges
+                .iter()
+                .filter(|edge| edge.kind == EdgeKind::Imports)
+                .all(|edge| building
+                    .nodes
+                    .iter()
+                    .any(|node| { node.id == edge.target && node.kind == NodeKind::File }))
+        );
+    }
+}
+
+#[test]
+fn secondary_languages_have_explicit_non_parity_characterization() {
+    let python = scan(&fixture_root("python")).unwrap();
+    let python_classes: Vec<_> = python
+        .nodes
+        .iter()
+        .filter(|node| node.kind == NodeKind::Class)
+        .map(|node| node.name.as_str())
+        .collect();
+    let python_functions: Vec<_> = python
+        .nodes
+        .iter()
+        .filter(|node| node.kind == NodeKind::Function)
+        .map(|node| node.name.as_str())
+        .collect();
+    assert_eq!(python_classes.len(), 2);
+    assert!(python_classes.contains(&"Base"));
+    assert!(python_classes.contains(&"Worker"));
+    assert_eq!(python_functions.len(), 2);
+    assert!(python_functions.contains(&"helper"));
+    assert!(python_functions.contains(&"start"));
+    assert_eq!(edge_count(&python, EdgeKind::Imports), 1);
+    assert_eq!(edge_count(&python, EdgeKind::Inherits), 1);
+    assert_eq!(edge_count(&python, EdgeKind::Calls), 1);
+
+    let swift = scan(&fixture_root("swift")).unwrap();
+    let swift_symbols: Vec<_> = swift
+        .nodes
+        .iter()
+        .filter(|node| matches!(node.kind, NodeKind::Class | NodeKind::Function))
+        .map(|node| node.name.as_str())
+        .collect();
+    assert_eq!(swift_symbols.len(), 2);
+    assert!(swift_symbols.contains(&"Worker"));
+    assert!(swift_symbols.contains(&"start"));
+    assert_eq!(edge_count(&swift, EdgeKind::Imports), 0);
+    assert_eq!(edge_count(&swift, EdgeKind::Inherits), 1);
+    assert_eq!(edge_count(&swift, EdgeKind::Calls), 1);
+}
+
+fn assert_fixture(case: FixtureCase) {
+    let root = fixture_root(case.directory);
+    let building = scan(&root).unwrap();
+    let mut classes: Vec<_> = building
+        .nodes
+        .iter()
+        .filter(|node| {
+            node.language.as_deref() == Some(case.language) && node.kind == NodeKind::Class
+        })
+        .map(|node| node.name.as_str())
+        .collect();
+    let mut functions: Vec<_> = building
+        .nodes
+        .iter()
+        .filter(|node| {
+            node.language.as_deref() == Some(case.language) && node.kind == NodeKind::Function
+        })
+        .map(|node| node.name.as_str())
+        .collect();
+    classes.sort_unstable();
+    functions.sort_unstable();
+
+    assert_eq!(classes, case.classes, "{} class baseline", case.directory);
+    assert_eq!(
+        functions, case.functions,
+        "{} function baseline",
+        case.directory
+    );
+    assert_eq!(
+        edge_count(&building, EdgeKind::Imports),
+        case.imports,
+        "{} import baseline",
+        case.directory
+    );
+    assert_eq!(
+        edge_count(&building, EdgeKind::Inherits),
+        case.inherits,
+        "{} inheritance baseline",
+        case.directory
+    );
+    assert_eq!(
+        edge_count(&building, EdgeKind::Calls),
+        case.calls,
+        "{} call baseline",
+        case.directory
+    );
+    assert!(
+        !building.nodes.iter().any(|node| matches!(
+            node.name.as_str(),
+            "CommentGhost" | "commentCall" | "comment_call" | "phantom_call"
+        )),
+        "{} block-comment clean negative",
+        case.directory
+    );
+}
+
+fn fixture_root(directory: &str) -> PathBuf {
+    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .join("tests/fixtures/languages")
+        .join(directory)
+}
+
+fn edge_count(building: &brick::Building, kind: EdgeKind) -> usize {
+    building
+        .edges
+        .iter()
+        .filter(|edge| edge.kind == kind)
+        .count()
+}