[metrics] Recalculate average after removing the last value - #301
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dajiaohuang wants to merge 1 commit into
Open
[metrics] Recalculate average after removing the last value#301dajiaohuang wants to merge 1 commit into
dajiaohuang wants to merge 1 commit into
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Summary
Fixes #300.
Removing the last numeric value during an incremental average update divides by zero. If the same transaction subsequently adds another row, the intermediate nonfinite result survives until Metrics exposes it as undefined, despite the final table having numeric data.
Return undefined from the removal shortcut when its prior length is one. This uses the existing full-recalculation fallback on the final values, without changing public APIs or other aggregators.
The regression removes the sole row, adds two rows in one transaction, checks the final average and single listener notification, and verifies a later update.
Validation
f09e5a3b74) and passes with this patch.npm run compileForTestpasses.git diff --checkpass for the patch. CSpell passes for the production file; repository configuration excludes test files.test/unit/core/other: 753 pass, 2 middleware synchronization tests fail (transformed data/value returning to the originator). Both fail identically after removing this patch and rebuilding main.npm run preCommitcould not complete on Windows: the spell stage fails withspawn npx ENOENT. Focused tests do not establish whole-repository 100% coverage.Tested on Windows with Node.js v24.14.1. No dependencies or generated files changed.