Support beam:logical_type:micros_instant:v1 in SpannerIo.

[claudevdm]

This adds support for the micros instant logical type in spanner IO reads and writes.

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[github-actions]

Assigning reviewers:

R: @shunping for label python.
R: @Abacn for label java.
R: @nielm for label spanner.

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[claudevdm]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds support for microsecond-precision timestamps (MicrosInstant logical type) in SpannerIO. The changes correctly handle the conversion between java.time.Instant and Spanner's Timestamp for both writing and reading data. The integration tests have also been updated to cover this new functionality.

My review focuses on improving code maintainability by reducing duplication and enhancing the completeness of the integration tests. I've identified a few areas where helper methods could be introduced to centralize conversion logic, and a couple of test cases where assertions could be made more robust.

[gemini-code-assist]

The logic to convert a java.time.Instant to a com.google.cloud.Timestamp with microsecond precision is duplicated in setBeamValueToKey, setBeamValueToMutation (lines 253-254), and addIterableToMutationBuilder (lines 384-387). To improve code clarity and maintainability, consider extracting this conversion into a private static helper method.

For example:

private static Timestamp toSpannerTimestamp(Instant instant) {
  long micros = instant.getEpochSecond() * 1_000_000L + instant.getNano() / 1_000L;
  return Timestamp.ofTimeMicroseconds(micros);
}

This new method could then be used in all three locations, simplifying the code.

[gemini-code-assist]

The logic to convert a com.google.cloud.Timestamp to a java.time.Instant is duplicated here and in getStructArrayValue (lines 437-440). To avoid duplication and improve maintainability, this logic should be extracted into a private static helper method.

For example, you could add:

private static java.time.Instant fromSpannerTimestamp(Timestamp spannerTimestamp) {
  long micros = spannerTimestamp.getSeconds() * 1_000_000L + spannerTimestamp.getNanos() / 1_000L;
  return java.time.Instant.ofEpochSecond(micros / 1_000_000L, (micros % 1_000_000L) * 1_000L);
}

And then call it here:

return fromSpannerTimestamp(spannerTimestamp);

[gemini-code-assist]

The assertions in this test case only validate the first row of the results. Since two rows are written to Spanner, it would be more robust to assert the contents of both rows to ensure the SpannerReplace transform works as expected for all inputs.

    results = self.spanner_helper.read_data(self.database_id, prefix='replace')
    self.assertEqual(len(results), 2)
    # In REPLACE, boolean should be NULL but timestamp should be updated
    self.assertEqual(results[0][0], 'replace0')
    self.assertEqual(results[0][1], 10)
    self.assertIsNone(results[0][2])  # boolean replaced with NULL
    self.assertIsNotNone(results[0][3])  # timestamp updated

    self.assertEqual(results[1][0], 'replace1')
    self.assertEqual(results[1][1], 11)
    self.assertIsNone(results[1][2])  # boolean replaced with NULL
    self.assertIsNotNone(results[1][3])  # timestamp updated

[gemini-code-assist]

The assertions for this test are incomplete. They only check some values of the first result row and do not check the second row at all. To make the test more robust, the assertions should be expanded to cover all relevant fields for both rows.

    results = self.spanner_helper.read_data(self.database_id, 'update')
    self.assertEqual(len(results), 2)
    # In UPDATE, boolean preserved but timestamp updated
    self.assertEqual(results[0][0], 'update0')
    self.assertEqual(results[0][1], 10)
    self.assertEqual(results[0][2], False)  # boolean preserved
    self.assertIsNotNone(results[0][3])  # timestamp updated

    self.assertEqual(results[1][0], 'update1')
    self.assertEqual(results[1][1], 11)
    self.assertEqual(results[1][2], False)  # boolean preserved
    self.assertIsNotNone(results[1][3])  # timestamp updated

[Abacn]

LGTM after dedup conversion logics suggested by AI code review

[nielm]

Please also implement the gemini code assist changes...

[nielm]

Please use a constant for this and in the expectedInstant calculations below

[nielm]

Please use a constant for this and the other locations it is used.