fix: NgxParserBaseException.__str__ raises TypeError when lineno is None

[gaoflow]

Problem

NgxParserBaseException.__str__ raises TypeError: not all arguments converted during string formatting when lineno is None.

The else-branch used self.args (a 3-tuple of (strerror, filename, lineno)) with a 2-placeholder format string:

return '%s in %s' % self.args   # self.args has 3 elements → TypeError

This is triggered whenever an error is caught without a line number, e.g. through crossplane.formatter.format() when the underlying parser error carries lineno=None, or from any code that wraps a non-NgxParser exception and passes lineno=None explicitly.

Fix

Use the named instance attributes directly in both branches, so the tuple passed to % always matches the format string:

return '%s in %s:%s' % (self.strerror, self.filename, self.lineno)
# and
return '%s in %s' % (self.strerror, self.filename)

Fixes #93.

Tests

Three new tests in tests/test_analyze.py cover:

• str() with a valid line number (regression guard)
• str() with lineno=None (the previously crashing case)
• same with a subclass (NgxParserSyntaxError)

All 48 tests pass.

---

This pull request was prepared with the assistance of AI, under my direction and review.