[magnusp]

Closes #31. Part of #54.

What changed

• getLong and getDouble now apply SQLite's text-to-number conversion instead of strict Long.parseLong/Double.parseDouble parsing.
• Blob values are decoded as UTF-8 text and then converted through the same path, matching sqlite-jdbc's handling of blob storage classes in numeric getters.
• getInt, getByte, and getShort inherit the conversion via getLong; getFloat inherits it via getDouble, so all numeric getters agree.
• Added LibsqlResultSetTest fixtures covering non-numeric text, numeric text, REAL text, exponent text, leading whitespace/trailing garbage, numeric blobs, non-numeric blobs, REAL storage, and INTEGER storage. Each case asserts getInt, getLong, getFloat, and getDouble.

Contract decision

Match xerial 3.53.4.0 (JDBC3ResultSet.java:304-350, backed by sqlite3_column_int64/sqlite3_column_double) as required by #54's drop-in-replacement goal:

• Text integral getters use sqlite3Atoi64 semantics: leading whitespace and sign, decimal prefix only, saturation on overflow, 0 when no digits. Thus '1.9' -> 1, '1.5e2' -> 1, 'abc' -> 0.
• Text floating getters use sqlite3AtoF semantics: leading whitespace and sign, decimal prefix with optional exponent, 0 when no mantissa digits.
• Blob bytes are interpreted as text and converted the same way: x'313233' -> 123, x'616263' -> 0.
• NULL remains 0 for numeric getters, with wasNull() still reporting true.

Evidence

Before the fix (new tests only):

./mvnw -pl libsql-jdbc -am test
...
[ERROR] Tests run: 13, Failures: 5, Errors: 0, Skipped: 0
[ERROR]   LibsqlResultSetTest.numericBlobIsInterpretedAsText:57->assertNumeric:90 expected: 123 but was: 0
[ERROR]   LibsqlResultSetTest.realTextBlobIsInterpretedAsText:64->assertNumeric:90 expected: 1 but was: 0
[ERROR]   LibsqlResultSetTest.realTextTruncatesForIntegralGettersAndKeepsFractionForFloatingGetters:36->assertNumeric:90 expected: 1 but was: 0
[ERROR]   LibsqlResultSetTest.textWithExponentUsesIntegerPrefixForIntegralGetters:43->assertNumeric:90 expected: 1 but was: 0
[ERROR]   LibsqlResultSetTest.textWithLeadingWhitespaceAndTrailingGarbageUsesNumericPrefix:50->assertNumeric:90 expected: 42 but was: 0

After the fix:

./mvnw -pl libsql-jdbc -am test
...
Tests run: 13, Failures: 0, Errors: 0, Skipped: 0
BUILD SUCCESS

./mvnw spotless:check
BUILD SUCCESS

Additional verification: an ad-hoc probe of the same conversion cases against xerial 3.53.4.0 produced identical getInt/getLong/getFloat/getDouble output for 29 inputs, including overflow, exponent, whitespace, and negative-zero cases.

Deviations

None.