[Copilot]

Coverage gaps existed in core parsing/token utilities around parser error recovery, quoted-identifier initialization paths, whitespace/comment filtering boundaries, and null/error-state branches in lightweight value objects. This PR adds focused unit tests to exercise those branches without changing production behavior.

• Parser recovery + constructor-path coverage (TSql180ParserTest)

  • Adds coverage for parse(null, errors) returning null without mutating error state.
  • Adds a malformed SQL case to validate syntax errors are surfaced through parse-error collection.
  • Exercises both TSql180Parser(true) and TSql180Parser(false) constructor paths to cover quoted-identifier initialization toggles.

• Whitespace/comment filter edge cases (TSqlWhitespaceTokenFilterTest)

  • Adds stream-backed and list-backed tests for:
    • adjacent multiline comments,
    • mixed comment/whitespace skipping,
    • EOF emission and last-token state.
  • Verifies AsciiStringOrQuotedIdentifier conversion behavior under quoted-identifier on/off modes.

• Token + parse-result null/error branches

  • TSqlParserTokenTest: adds null token-type constructor case to validate fallback to TSqlTokenType.None and underlying ANTLR type 0.
  • ParseResultTest (new): adds null-errors/immutable-empty-list and non-empty-errors branches, including isSuccess()/hasErrors()/toString() behavior.

// New branch coverage example: null token type fallback
TSqlParserToken token = new TSqlParserToken(null, 7, "?", 3, 4);
assertThat(token._getTokenType()).isEqualTo(TSqlTokenType.None);
assertThat(token.getType()).isZero();

• Fixes Add unit test coverage for TSql180Parser error recovery, tokens, and filter edge cases #29

[Copilot]

🟢 Approval recommended

The change is additive, test-only with no production behavior change, and each new assertion was verified to match the existing production code.

0 open findings

What changed in this PR

This PR adds focused unit tests to close SonarCloud coverage gaps in the tsql-scriptdom-core parser/token utilities (issue #29). No production code is modified; the tests exercise previously uncovered branches in parser error recovery, quoted-identifier initialization, whitespace/comment filtering boundaries, and null/error-state handling in lightweight value objects. I verified each new assertion against the corresponding production code (TSqlWhitespaceTokenFilter, TSqlParserToken, TSql180Parser, ParseResult) and found them consistent with actual behavior; imports are present, and every TRACEABILITY_MAPPING references a requirement that exists in context/SRS.md.

Changes:

• Adds TSql180ParserTest cases for parse(null, errors), malformed-SQL error collection, and both quoted-identifier constructor paths.
• Extends TSqlWhitespaceTokenFilterTest with adjacent-comment/EOF-boundary, inner-stream skip-to-EOF, and AsciiStringOrQuotedIdentifier conversion-flag tests.
• Adds a null-token-type fallback test (TSqlParserTokenTest) and a new ParseResultTest covering null/non-empty error branches and immutability.

File	Description
tsql-scriptdom-core/​src/​test/​java/​io/​github/​fupacat/​TSql180ParserTest.java	Adds null-reader, syntax-error, and quoted-identifier constructor coverage.
tsql-scriptdom-core/​src/​test/​java/​io/​github/​fupacat/​TSqlWhitespaceTokenFilterTest.java	Adds list-backed and inner-stream filter edge cases plus conversion-flag checks.
tsql-scriptdom-core/​src/​test/​java/​io/​github/​fupacat/​TSqlParserTokenTest.java	Adds null token-type fallback to None/ANTLR type 0.
tsql-scriptdom-core/​src/​test/​java/​io/​github/​fupacat/​ParseResultTest.java	New test for null/non-empty error branches, immutability, and toString.

🧠 Review effort: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

🟡 Changes recommended

testParseSyntaxErrorIsCollected asserts a non-null fragment for malformed SQL, but the defaultErrorHandler=false grammar causes _parse to return null, so the test will fail.

1 open finding

• Invalid syntax parse returns null fragment, not a value · New

🧠 Review effort: Balanced

[Copilot]

🟢 Approved

Test-only additions whose assertions I verified line-by-line against the production code, with valid symbol references and correct REQ traceability mappings.

1 open finding

• Invalid syntax parse returns null fragment, not a value

🧠 Review effort: Balanced