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Fix IllegalStateException when typing an unterminated string in Go - #9660
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…pache#9654) Typing a double quote as the last characters of a Go document made the lexer infrastructure throw: IllegalStateException: Lexer ...GoLangLexer returned null token but lexerInput.readLength()=6 Root cause: an unterminated literal at the end of the text makes the ANTLR lexer throw LexerNoViableAltException, after which it emits an end-of-input token while characters are still pending on the LexerInput. AbstractAntlrLexerBridge.nextToken() then returned null, but the consumed characters still needed a token. Fix it once in AbstractAntlrLexerBridge: when the ANTLR lexer reports end of input with pending input, delegate to mapToken() so the pending characters receive a token (implementations map EOF to an error-ish token in their default branch). A true end of input (readLength()==0) still returns null as before. Also fix TomlLexer.mapToken(), the only override of the nine ANTLR-backed languages that explicitly returned null for EOF, so it returns an ERROR token instead. Adds GoLangLexerTest as a regression test covering the issue text, unterminated rune and raw string literals, and that well formed text stays unaffected. Assisted-by: mimo-v2.6-flash-free
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🟢 Approval recommended
The shared lexer fix is consistent with existing mappings and is covered by focused regression tests.
Review effort: Balanced
Findings: None
What changed in this PR
Fixes unterminated Go strings causing lexer failures by tokenizing pending input at EOF.
Changes:
- Maps EOF with pending characters through each lexer’s token mapping.
- Handles TOML EOF as an error token.
- Adds Go lexer regression tests and JUnit support.
| File | Description |
|---|---|
AbstractAntlrLexerBridge.java |
Handles pending input at EOF. |
TomlLexer.java |
Maps pending EOF input to ERROR. |
GoLangLexerTest.java |
Adds lexer regression coverage. |
project.xml |
Adds JUnit 4 test dependency. |
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mbien
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| private static final String ISSUE_9654_TEXT = "package main\n" | ||
| + "\n" | ||
| + "import (\n" | ||
| + " \"fmt\"\n" | ||
| + ")\n" | ||
| + "\n" | ||
| + "func main() {\n" | ||
| + " fmt.Println(\")\n" | ||
| + "}\n" | ||
| + "\n"; |
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lets use multi line strings for new tests. I just converted the maven tests -> much easier to read once something fails.
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Closes #9654
In AbstractAntlrLexerBridge: when the ANTLR lexer reports end of input with pending input, delegate to mapToken() so the pending characters receive a token (implementations map EOF to an error-ish token in their default branch). A true end of input (readLength()==0) still returns null as before.
Assisted-by: mimo-v2.6-flash-free
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