fix(java): link new-expression to constructor and class instantiation

[vitali87]

Found by dogfooding the dead-code eval on google/gson (Java's first dead-code dogfood). Drives gson core from 114 to 92 false positives by fixing the single largest class.

The class: Java new X(...) never linked to constructors

SPEC_JAVA_CALL_TYPES collected only method_invocation, never object_creation_expression, so new X(...) produced no INSTANTIATES edge to the class and no CALLS edge to the constructor. Every constructor reached only via new therefore looked dead (45 of gson's 114 false positives).

Fix (mirrors the JS new_expression / Python class-call path)

1. Add object_creation_expression to SPEC_JAVA_CALL_TYPES.
2. _get_call_target_name names a Java object_creation_expression by its type field (strips generic args, e.g. new ArrayList<T>() -> ArrayList; a scoped Outer.Inner is left for the resolver), routing construction through the normal resolve loop.
3. At the emit site, a resolved class node gets INSTANTIATES plus a CALLS edge to each declared constructor via the new java_constructor_targets helper. A Java constructor is registered as a method named like its class (Foo.Foo(int)); the helper matches only constructors DIRECTLY on the class (a nested class's constructor has an extra qn segment and is excluded). Argument-type overload selection is not attempted, which is unnecessary for reachability and never fabricates a call to a non-constructor.

Tests

test_java_constructor_calls.py: a new X(...) both instantiates the class and calls the constructor; an overloaded class has every constructor reached.

Verified: gson 114 -> 92, full suite green (4427 passed), 522 Java tests pass, no cross-language effect (every new path is language == JAVA-gated).

[gemini-code-assist]

Code Review

This pull request adds support for tracking Java object creation expressions (new Foo(...)) as call nodes. It updates constants, handles TS_OBJECT_CREATION_EXPRESSION in the call processor to resolve the class name, and routes CALLS edges to all declared constructors of the instantiated class. Additionally, a new test suite is added to verify these relationships. There are no review comments, so I have no feedback to provide.

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[greptile-apps]

Greptile Summary

This PR links Java new X(...) expressions to class instantiation and constructor reachability. The main changes are:

• Adds object_creation_expression to Java call node collection.
• Captures Java object creation types broadly, including generic and scoped type nodes.
• Resolves Java new expressions through the existing call resolver path.
• Emits INSTANTIATES edges to classes and CALLS edges to declared constructors.
• Adds tests for simple, overloaded, generic, and nested constructor expressions.

Confidence Score: 5/5

Safe to merge with minimal risk.

The change is tightly scoped to Java object creation handling and keeps the new behavior language-gated. The constructor path includes guards for non-class targets and tests for the key simple, overloaded, generic, and scoped cases.

No files require special attention.

T-Rex Logs

What T-Rex did

• Verified the initial tool and language environment; uv 0.11.27 and Python 3.11.6 were available (per general-contract-validation-proof).
• Attempted to run the narrow pytest command; CPython 3.12.13 was downloaded and environment creation started, but building pymgclient==1.5.1 failed due to cmake tooling being inaccessible.
• As a result, pytest execution did not occur and constructor instantiation/CALLS edge behavior could not be validated in this environment.

_{Ran code and verified through T-Rex}

Important Files Changed

Filename	Overview
codebase_rag/constants.py	Adds Java object creation expressions to the call-node types so constructor invocations enter call processing.
codebase_rag/language_spec.py	Broadens the Java object-creation query to capture any type node, covering generic and scoped constructor names.
codebase_rag/parsers/call_processor.py	Names Java new expressions from their type field and emits instantiation plus constructor call relationships for resolved class targets.
codebase_rag/parsers/call_resolver.py	Adds direct Java constructor target discovery under a resolved class qualified name.
codebase_rag/tests/test_java_constructor_calls.py	Adds tests for simple, overloaded, generic, and scoped Java constructor instantiation paths.
uv.lock	Updates the editable package version from 0.0.253 to 0.0.256.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
participant JavaAST as Java AST
participant Query as LANGUAGE_SPECS call_query
participant Processor as CallProcessor
participant Resolver as CallResolver
participant Graph as Graph relationships

JavaAST->>Query: object_creation_expression type capture
Query->>Processor: call_node new X(...)
Processor->>Processor: extract type name and strip generic args
Processor->>Resolver: resolve_function_call(type_name)
Resolver-->>Processor: resolved class qualified name
Processor->>Graph: "INSTANTIATES caller -> class"
Processor->>Resolver: java_constructor_targets(class_qn)
Resolver-->>Processor: direct declared constructors
Processor->>Graph: "CALLS caller -> constructor(s)"

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sequenceDiagram
participant JavaAST as Java AST
participant Query as LANGUAGE_SPECS call_query
participant Processor as CallProcessor
participant Resolver as CallResolver
participant Graph as Graph relationships

JavaAST->>Query: object_creation_expression type capture
Query->>Processor: call_node new X(...)
Processor->>Processor: extract type name and strip generic args
Processor->>Resolver: resolve_function_call(type_name)
Resolver-->>Processor: resolved class qualified name
Processor->>Graph: "INSTANTIATES caller -> class"
Processor->>Resolver: java_constructor_targets(class_qn)
Resolver-->>Processor: direct declared constructors
Processor->>Graph: "CALLS caller -> constructor(s)"

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_{Reviews (2): Last reviewed commit: "fix(java): capture generic and scoped ne..." | Re-trigger Greptile}

[codecov-commenter]

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[vitali87]

@greptile review

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud