temper

# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

## [0.3.0] - 2026-09-01

### Added

- CI Recipes guide on hexdocs: GitLab CI and CircleCI persistence
  recipes (cache semantics per provider, parallel-job lineages), the
  artifact download-and-merge flow for inspecting history locally,
  and keeping a cached history bounded with the retention flags. The
  README keeps the GitHub Actions recipe and links the guide.

- History Schema guide on hexdocs: the JSONL line format (schema v1)
  documented as a public contract — envelope, every field with type
  and nullability, failure signatures, suite lines, consumer and
  producer rules, and the versioning policy (additive within v1,
  breaking changes bump the `schema` number).

- `mix temper.clean --older-than DAYS` and `--keep-shas N` prune
  history instead of deleting it: files are rewritten in place
  keeping only lines inside the retention window, emptied files are
  removed, and corrupt lines are dropped with a count. A criterion
  only drops lines it can positively match — lines without a SHA
  (suite summaries, null-SHA records) are untouched by `--keep-shas`
  and age out via `--older-than`. Keeps a history persisted across
  CI runs bounded.

- `mix temper.merge --output FILE [GLOBS...]` merges history files
  into one deduplicated file — the aggregation step for CI artifact
  flows (one `.temper/` artifact per job, download, merge, report)
  and for compacting overlapping cache restores. Input globs match
  into dot-directories (artifact downloads keep history inside
  `.temper/`). Dedupe is byte-exact on whole lines; lines this
  version does not interpret (suite summaries, future schema
  versions) are preserved verbatim, and only corrupt lines are
  skipped, with counts reported.

### Changed

- `mix temper.doctor` dates a partial SHA gap: the `recorded commit
  SHAs` warning now reports the newest null-SHA record's timestamp and
  whether the gap is still occurring or every record since carries a
  SHA — legacy noise and an active recording-blind path are
  distinguishable at a glance.

## [0.2.1] - 2026-08-25

### Added

- `{partition}` placeholder in `history_path`: the formatter expands
  it with the `MIX_TEST_PARTITION` value (`"0"` when unset) and
  `mix temper.report` / `mix temper.clean` widen it to `*` — custom
  paths are partition-safe by construction instead of by recipe.
- README FAQ answering the first real-world questions: whether Temper
  re-runs tests, cross-commit failures, what "Suspects" means, and
  why a first run reports nothing.
- `mix temper.doctor` — setup preflight diagnosing the silent failure
  modes: formatter not registered for the test env, `history_path`
  invisible outside the test env, umbrella child apps whose app-dir
  runs record nothing, empty history, and records without a usable
  commit SHA. Exits non-zero on problems so CI can gate setup on it.

## [0.2.0] - 2026-08-23

### Added

- `TEMPER_SHA`, `TEMPER_DIRTY` and `TEMPER_BRANCH` environment
  variables override git context detection — for containers and other
  environments where git cannot answer. A non-empty `TEMPER_SHA`
  activates manual mode and takes priority over CI variables and
  local git.
- `mix temper.report --by-app` groups findings by umbrella child app
  (derived from file paths), with per-app counts and involved files.
  JSON findings always carry the derived `"app"` field.

### Changed

- Recommended dependency line is now
  `only: [:dev, :test], runtime: false`, keeping `mix temper.report`
  available in the default env.
- Documented umbrella setup: root-only dependency, formatter
  registration via `config :ex_unit`, and a partition-safe shared
  history path — verified end-to-end on Elixir 1.15 through 1.20.

## [0.1.0] - 2026-08-22

### Added

- `Temper.Formatter` — ExUnit formatter recording every test outcome to
  `.temper/history-{partition}.jsonl`, with run context (git SHA, dirty
  flag, CI provider, seed, partition) and failure signatures.
  Crash-safe: on any internal error it warns once and goes inert.
- `mix temper.report` — flaky tests (divergent outcomes on the same
  clean git SHA) sorted by flake rate, plus lower-confidence suspects
  from dirty-tree runs. Options: `--json`, `--min-runs`, `--history`.
- `mix temper.clean` — deletes recorded history.
- History schema v1: append-only JSONL, one denormalized line per test
  outcome, partition-safe for parallel CI jobs.