WEBKIT-BOX 1: display parses as Chrome 145; -webkit-box refused precisely, -webkit-flex as flex

[thejackshelton]

WEBKIT-BOX (1): display now parses exactly as Chrome 145 does. display: -webkit-box and -webkit-inline-box were called invalid; Chrome parses them, so Dragon now refuses them with a precise reason instead.

What changed

• Grammar (scripts/gen-css-grammar.ts, new SYNTAX_OVERRIDES): display takes Chrome 145's grammar, from Blink Display::ParseSingleValue and ParseDisplayMultipleKeywords, in place of webref's.
  • Now parsed: -webkit-box, -webkit-inline-box, -webkit-flex and -webkit-inline-flex. Blink's legacy keyword range runs from inline-block to -webkit-inline-flex.
  • Now invalid, because Chrome drops them: run-in (alone or in a list), grid-lanes and inline-grid-lanes (CSSGridLanesLayout is off in 145), ruby-base, ruby-base-container and ruby-text-container. Before this PR they parsed and were then refused as unsupported. That was a wrong acceptance: Chrome drops the declaration and an earlier one wins.
• css/display-legacy.ts (called from parseValue):
  • -webkit-flex and -webkit-inline-flex become flex and inline-flex, which is how Chrome computes them (Blink has no EDisplay of their own). The web output emits flex.
  • -webkit-box and -webkit-inline-box are refused on every target with DRAGON_UNSUPPORTED_VALUE: "display: -webkit-box is unsupported: it selects Chrome's legacy -webkit-box layout, which Dragon does not lay out, line clamping with -webkit-box-orient: vertical and -webkit-line-clamp included". The span is the keyword. The fix says to use flex or inline-flex. A var() that substitutes one of them gets the same reason.
• Fixture group display-legacy:
  • display-webkit-flex (ltr and rtl): a -webkit-flex row, a column, a blockified -webkit-inline-flex item, and an upper-case -WEBKIT-FLEX.
  • Rejects: reject-display-webkit-box and reject-display-webkit-inline-box, both the line-clamp pattern, and reject-display-run-in.

Line clamping is not in this PR

The TXT2 spec (notes/T149-txt2-spec.md R11, part TXT2-g) owns -webkit-line-clamp, -webkit-box-orient and the -webkit-box adjustment to flow-root. This PR does not duplicate that work. TXT2-g will lift this refusal for its accepted combination, in display-legacy.ts or in a per-element check. The general legacy box (-webkit-box-pack/align/flex/direction/ordinal-group) does not map cleanly onto flexbox. Blink lays it out through its own -webkit-box paths, and it is not fixed by display alone, so it stays refused. Those properties keep DRAGON_UNSUPPORTED_PROPERTY.

Proof

• packages/parity/test/display-parse.test.ts (live Chrome 145.0.7632.6). It covers 1,095 display values: every keyword (including case variants), every two-keyword list over 18 keywords, and every three-keyword list over 9.
  • Dragon accepts a value exactly when Chrome parses it, with no gap list.
  • Each accepted value computes in Chrome the same as Dragon's value.
  • Every refusal is of a value Chrome parses. The only single-keyword refusals are the legacy box keywords. Three-keyword lists keep their existing multi-token refusal.
  • Three planted readings are each caught on every item: webkitFlexAsBlock, runInAccepted and webkitBoxInvalid.
• packages/dragon/test/display-legacy.test.ts (14 tests): the refusal message, span, fix, blocked outputs and catalogue on every target, through var(), and with the line-clamp pattern. It also checks that -webkit-flex emits the same web CSS as flex, that -webkit-inline-flex gets the same diagnostics as inline-flex, that the autoprefixer chain compiles, and that the dropped values are invalid.
• I ran the four new fixtures through runFixture with live Chrome: all pass, including display-webkit-flex-rtl.

What passed (base origin/master 65e91d9)

• pnpm typecheck: clean.
• Targeted tests: display-legacy.test (14/14), display-parse.test (1/1), blockify, both registry-claims tests, diagnostics, s5, media-wiring, compile, grid-computed, tailwind-sweep units and fixture-reader: all passed.
• Regen: through the regen label (regen-on-ci). The grammar output and the new fixture captures land in the bot's commit.

Expected regen and sweep movement

• tw-sweep: line-clamp-1..6 move from refused DRAGON_CSS_INVALID_VALUE ... chrome-parses to a refusal Dragon no longer calls invalid.
• Coverage rank: no ranked row becomes supported. The rank counts properties, and -webkit-line-clamp / -webkit-box-orient stay TXT2's. The -webkit-line-clamp blocker changes from CSS_INVALID_VALUE (-webkit-box) to the precise refusals.

Outside the spec

• docs/goals/milestone-2-proof/notes/TW-SWEEP.md:39 still says Dragon calls -webkit-box invalid. It is under docs/goals, so I left it for the PM.

🤖 Generated with Claude Code

[thejackshelton]

Landing stopped at step test (pnpm land)

packages/parity/test/css-escapes.test.ts, rerun alone on a quiet machine, exited 1 (log /tmp/land-181-test-solo-1.log)
 ❯ packages/parity/test/css-escapes.test.ts:415:38
    413|     }
    414|     expect(new Set(twins.map((t) => t.decl)).size).toBe(twins.length);
    415|     expect(twinFloorProblems(twins)).toEqual([]);
       |                                      ^
    416|   });
    417| });

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯


 Test Files  1 failed (1)
      Tests  1 failed | 1 passed (2)
   Start at  12:42:04
   Duration  1.81s (transform 216ms, setup 0ms, import 275ms, tests 1.48s, environment 0ms)

Found by bisecting the batch #181 #185 #186 (2 proofs): master passes, adding #181 fails.

Fix the cause, then hand #181 back to the landing queue with the new clean head.

[thejackshelton]

Landing failure fixed in 45a1141: css-escapes display twin floor (27 < 33). The six keywords Chrome 145 drops (run-in, grid-lanes, inline-grid-lanes, ruby-base, ruby-base-container, ruby-text-container) are now escape twins asserted invalid in Dragon, escaped and plain, and dropped by Chrome both ways; the four legacy -webkit- keywords (which reach() skips for their leading hyphen) are twins too. display now has 37 plain spellings with twins; floor unchanged. css-escapes, display-parse, display-legacy, registry-claims and blockify pass; typecheck clean.

[thejackshelton]

Landing stopped at step merge (pnpm land)

merge-train: merging webkit-box onto 7526bbf73cb0dbb9cd2c9ca58898ae10d92c4090 failed; conflicts in packages/parity/src/fixtures.ts

Fix the cause, then hand #181 back to the landing queue with the new clean head.

[thejackshelton]

Landing stopped at step test (pnpm land)

packages/parity/test/hit-capture-identity.test.ts, rerun alone on a quiet machine, exited 1 (log /tmp/land-181-test-solo-1.log)
 ❯ packages/parity/test/hit-capture-identity.test.ts:64:56
     62|   it('holds only SELD-R1b fixtures\' files beyond the base', () => {
     63|     const extra = IDENTITY_ROOTS.flatMap(walk).filter((p) => (p.endsWi…
     64|     expect(extra.filter((p) => !IDENTITY_NEW.test(p))).toEqual([]);
       |                                                        ^
     65|     expect(extra.length).toBeGreaterThan(0);
     66|   });

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯


 Test Files  1 failed (1)
      Tests  1 failed | 5 passed (6)
   Start at  15:42:33
   Duration  1.73s (transform 995ms, setup 0ms, import 1.31s, tests 356ms, environment 0ms)

Fix the cause, then hand #181 back to the landing queue with the new clean head.