3.2.0

Changed

• Breaking: a generated preview's snapshot is named after the file and function that declare
  it, e.g. MugshotChipCatalog.MugshotChipCatalogPreview.Light, rather than after its package
  path with underscores. The name is both the golden image's filename and what the test runner
  reports, so this shortens the line a run prints as well. Re-record with recordMugshot* and
  delete the goldens under the old names; the processor fails the build if two previews would
  now share a name.
• Breaking: the standalone snapshot gallery is gone, and HtmlReportWriter with it. It was
  written only by recordMugshot*, so verifyMugshot* printed a link to a report that did not
  exist. Recording now uses SnapshotRecorder, which writes goldens and nothing else.
• Breaking: Mugshot.snapshot takes a source between name and the composable, and
  MugshotPreviewCase takes a source after snapshotName. Kotlin callers of snapshot { } and
  snapshot("label") { } are unaffected, but anything compiled against an earlier version needs
  recompiling.
• A test run is quiet. The framework's log priority was discarded and every message logged at
  info, so each render put its verbose and debug lines in front of whoever ran the tests; the
  priority is now mapped to a matching level. The framework's own resources carry duplicate style
  definitions, and those are no longer warned about. The Byte Buddy agent Mugshot attaches is
  declared, so the JVM stops warning that an agent was loaded dynamically.
• A failed snapshot is reported as three labelled images, the golden, the difference between them,
  and this run's render, rather than one combined image behind a toggle. The report link points
  at the test report, which is where those images now appear.
• A failure from a generated preview names the screen's own declaration, e.g.
  com.example.feature.profile.ProfileScreen(ProfileScreen.kt:31) [Dark_Default], rather than the
  generated test class, which is the same for every preview in a module. The (File.kt:line) tail
  is the shape an IDE turns into a link. Hand-written tests are unchanged: they render an arbitrary
  composable, so there is no screen to name, and the message still uses the snapshot's name.
• A failure from a hand-written test names the test as a qualified name, e.g.
  com.example.screen.ScreenSnapshotTest.profile, rather than the golden image's filename. A test
  renders an arbitrary composable, so there is no screen to name and the test itself is the most
  specific thing there is.
• The report drops the exception class and the source location from a snapshot failure. The
  location is there so a console can turn it into a link, which a page cannot do, and the class is
  the same on every one. Other failures keep both.
• The failure message is three lines: what failed and by how much, the golden to update, and the
  difference image. It used to add the rendered image's path, a mv command, and a copy of itself
  on standard output, which buried the part worth reading. It is also thrown without a stack,
  since every snapshot failure carried the same frames of JUnit and Gradle plumbing.
• The difference image marks a changed pixel in flat ruby red and leaves everything else white.
  It used to shade each pixel by how far every colour channel had moved, which encoded the
  direction and size of the change but was hard to read, and wrapped around to near-grey on the
  largest changes. The white background replaces a transparent one, which blended into the page
  and left no way to see where the render ended. Pixels that differ by little enough to pass are
  no longer marked either, since they are not something to act on.

Added

• Verification writes reference- and diff- images alongside the render in
  build/mugshot/failures, so CI can collect the panels individually. The combined image the
  console error links to is still written, with its labels, since nothing else identifies the
  panels when it is opened on its own.
• mugshot-preview-lints is published. It was built and tested on every run but its publish plugin
  was commented out, so nobody could depend on it. Add it with lintChecks to have a @Mugshot
  preview that cannot produce a golden reported as a lint error rather than skipped in silence.

Removed

• Breaking: the mssim, sift, flip and de2000 image differs are gone, leaving offbytwo
  (the default) and pixelperfect. Setting uk.co.fractalmotion.mugshot.differ to a removed value
  now fails with Unknown differ type rather than falling back silently.
  The four measured worse on the job they were being asked to do. Against a 600x1000 golden with an
  80x20 block painted into it, a change nobody could miss, flip reported Identical and mssim,
  sift and de2000 reported Similar, so none of them would have failed a build. Only the two
  that survive reported Different. They were also 8 to 30 times slower: 82ms to 260ms per
  comparison against 9ms.
  sift had two further defects. It reported two identical images as different whenever they held
  no detectable features, so any flat colour or blank screen failed against itself, and it ran out
  of heap on a full screen render.