fix: Include location info in NumberFormatException from JsonReader#3000
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eamonnmcmanus merged 5 commits intogoogle:mainfrom Apr 23, 2026
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JsonReader.nextDouble(), nextInt(), and nextLong() call Double.parseDouble() on peeked strings, but the NumberFormatException thrown by parseDouble() contains no JSON location information (line, column, path), making it difficult to locate the problematic value in the input. Catch the NumberFormatException and rethrow with a message that includes the location string, consistent with other error messages in JsonReader. Fixes google#1564
Address the ErrorProne UnusedException warning (-Werror on JDK 25 / Build Gson subset CI jobs) introduced when the three number-parsing catch blocks in JsonReader were added: set the caught exception as the cause of the rethrown one so debuggers still see the original parse failure.
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Problem
JsonReader.nextDouble(),nextInt(), andnextLong()callDouble.parseDouble()on peeked strings. When parsing fails (e.g., for empty strings like""), theNumberFormatExceptionthrown byDouble.parseDouble()contains no JSON location information (line, column, path). This makes it difficult to locate the problematic value in the input JSON.For example, parsing
{ x: ''}as an int producesNumberFormatException: empty Stringwith no indication of where in the JSON the error occurred.Root Cause
The three methods had a comment
// don't catch this NumberFormatException.and let the exception fromDouble.parseDouble()propagate directly. OtherNumberFormatExceptionthrows in the same methods already include location information vialocationString().Fix
Catch the
NumberFormatExceptionfromDouble.parseDouble()and rethrow with a descriptive message that includes the location string, consistent with other error messages inJsonReader. The message format follows the existing pattern:"Expected a <type> but was <value> at line X column Y path $.<path>".Tests Added
testNextDoubleNumberFormatExceptionContainsLocation— verifies location in path$[0]testNextIntNumberFormatExceptionContainsLocation— verifies location in path$.xtestNextLongNumberFormatExceptionContainsLocation— verifies location in path$.yImpact
Only affects the error path when
Double.parseDouble()fails on an invalid numeric string. The exception type (NumberFormatException) is unchanged. All 4589 existing tests pass.Fixes #1564