Each README and JSDoc example now assigns the function that takes the
handler object (the factory result, or the tagged key step) to a match…
variable and reuses it, so the builder is created once instead of per
call.
The builder types are already the inferred return types and travel into
the emitted .d.ts, so exporting them only made them nameable while
pinning the internal Strict/Widening split as API. Revert the type
exports and the public renames, drop the type-surface test, and document
only the factories in README and development/library.md.
State that the `W` suffix means widening and what that widens: the
matcher's return value goes from one common `R` to the union of every
handler's return type.
Export the matcher builder types from the barrel and rename them off the
internal Strict/Widening suffixes, so the type a factory returns is
nameable: PrimitiveUnionMatcher/W, TaggedUnionMatcher/W, and the
tagged-union factory types. Add TSDoc to every public symbol — the
declarations carry it into the published package — and pin the exported
names in src/index.test.ts.
Document the API in README and record the surface decision (and the
rejected matcher-shared export) in development/library.md.
test:ci now runs c8 with --all --include "src/**/*.ts" --100, so the
build job fails when any runtime file under src/ is untested. --all is
what makes the gate non-vacuous: without it c8 counts only the files the
suite happened to load, and a new untested module stays invisible.
Add src/index.test.ts to load the public barrel, which was previously
never imported at runtime and so read as 0% under --all. matcher-shared.ts
is types-only (an empty runtime image) and carries a file-level c8 ignore
with the reason.
Why 100% and the rejected alternatives: development/ci.md § Coverage
threshold.
Add a README Caveats subsection with user-facing guidance for the two
open-universe shapes: parse external input at the boundary down to a
finite union, or use a runtime Map registry for extensible domains.
Point the finite-universe bullet at it, and point the rejected
fix/open-universe-* entry in development/library.md back at the new
guidance, so rule and decision cross-reference without duplicating each
other.
Add property-union tests for the completion popup, a broad value in the
union, and value/stringification collisions. Rename the existing
property-union tests to a `property union:` prefix so they can be
selected with `--test-name-pattern`, and extend the autocomplete helper
with a `key` option so a probe can complete on a property other than
`kind`.
`UnsupportedReason` tested `IsLiteral<PatternKey<T>> extends false`.
`IsLiteral` is `boolean` for a union that mixes a literal with a broad
type (`"a" | \`x-${number}\``), so `boolean extends false` is false and
the mix was accepted. Test `extends true` instead, which rejects it.
Found while adding property-union broad-universe coverage; the gate is
shared with the primitive-union matcher.
The tagged-union matcher selected handler parameters with
`Extract<T, Record<K, V>>`, which only keeps a member whose
discriminant is a singleton literal. A property that is itself a
union (`{ color: "red" | "green" | "blue" }`) or optional
(`{ type?: "x" }`) matched no member, so every handler received
`never`, and the fallback saw the whole shape instead of the
unhandled tags.
Replace the selector with `Narrowed`, which distributes over `T`,
drops a member whose `K` cannot take the tag, and narrows `K`. The
`T[K] extends V` fast path keeps an exact member (a discriminated
union's declared interface) untouched. The fallback reuses
`Narrowed` over `Exclude<Tags, HandledTags>`, so a union-valued
property narrows to the unhandled tags rather than the whole shape.
Matching a defined tag on an optional property makes the key
required (`{ type: "x" }`); the `undefined` tag yields
`{ type?: never }` under `exactOptionalPropertyTypes` (absence) or
`{ type?: undefined }` when the property admits an explicit
`undefined`.
Remove every done/cancelled backlog item; the reasons they recorded are
already in development/ (library.md, testing.md, tooling.md, workflow.md)
and git history is the archive.
The one exception was the TS 7 LSP shutdown workaround, which lived only in
a code comment. Record it under development/testing.md § Autocomplete
(Known issue) before dropping the bug item.
Listing scripts/*.ts in knip's `entry` replaced its default entry
detection, which derives the public entry from package.json `exports`.
Adding the CLI scripts therefore dropped the library entry, so knip
resolved the package through dist/index.js and flagged the unreferenced
src/index.ts as unused. Name the source entry alongside the scripts.
Record the rationale in development/tooling.md.
Bump every direct dependency to the latest registry version: cspell
10.3.3, knip 6.38.0, oxfmt 0.70.0, oxlint 1.85.0, oxlint-tsgolint
7.0.2002 and type-fest 5.10.0, plus their transitive updates. oxfmt is
the only range widened (^0.68.0 -> ^0.70.0); the rest moved within
their existing semver ranges.
`npm run maintain:outdated` is now clean and `npm run verify` is green
with no rule or format fallout. `maintain:knip` still reports the
pre-existing `src/index.ts` false positive (dist-only `exports`), which
predates this bump.
Record why open universes and value/stringification collisions are
rejected, the `Member<T, K>` inversion, and the findings from the
rejected open-universe attempt so they are not re-run.
An open universe (`string`, `number`, a template literal) makes the
handler map index-like, so a partial object satisfied the exhaustive
overload and the runtime `dispatch` throw was reachable. A universe
containing a member and its stringification (`"true" | true`, `1 | "1"`)
collapsed two members onto one key.
- reject broad universes and value/stringification collisions at the
factory, with a diagnostic naming the reason
- invert `PatternKey` against the universe (`Member<T, K>`) instead of
`PatternParam<K>`, so a standalone `"true"` is typed `"true"`
- intersect `UniverseGate<T>` into the handler and fallback parameters,
preserving `R` inference and the popup
Rename `MatcherStrict` / `MatcherWidening` to
`PrimitiveUnionMatcherStrict` / `PrimitiveUnionMatcherWidening`, matching
the exported `getPrimitiveUnionMatcher(W)` names and the
`TaggedUnionMatcher*` pair.
Folds in the working-tree lint cleanups: drop the now-unneeded
`typescript/unified-signatures` disables and turn the tagged-union
factory interfaces into type aliases.
A `boolean` / `null` / `undefined` discriminant cannot key a handler
map, so the tagged-union matcher now routes it through the
`PatternKey` / `PatternParam` projection the primitive-union matcher
already used. Both matchers share the projection from
`matcher-shared.ts`; `MapTaggedUnion`, `Handlers`, `HandledMembers`
and `MustBePartial` key off the projected form and invert it to
recover the real member.
Covers exhaustive and fallback dispatch, the redundant-fallback
guard, and the LSP popup offering the tags by name.
`getMatcher` / `getMatcherW` become `getPrimitiveUnionMatcher` /
`getPrimitiveUnionMatcherW`; `src/primitive.ts` and its test move to
`src/primitive-union.*`. The `Union` suffix mirrors `getTaggedUnionMatcher`.
Record the non-exhaustive broad-type hole in the primitive matcher and the
never-typed handler parameters the tagged-union matcher produces when a
property is a union, so both can be picked up as their own work units.
A handler's `expectTypeOf(shape)` only proved the type the compiler inferred;
nothing observed the argument `dispatch` passed. Passing `String(shape)` at the
call site therefore kept the whole suite green while breaking every key whose
property name differs from its value (`true`, `null`, `1`).
Pair each handler expectation with a runtime assertion: `assert.equal` where a
handler runs for one shape, the disjunction over the set a `_` fallback accepts
where it runs for several. Where the exact value matters the fallback returns
its shape verbatim and the call site asserts it; a widening pattern absorbs the
remainder type into the return union, so the claim stays strict-free. The
mutation above now fails 10 of the 33 tests.
Rule: CONTRIBUTING.md, rationale: development/testing.md § Handler arguments.
String(shape) defeats V8's numeric-key fast path (measured ~2x on
number-keyed dispatch). JS already coerces boolean/null/undefined to the
same property key, so assert shape to string | number and index directly.
The assertion is TS2538-only; the facade keeps it sound. Needs a source
no-unsafe-type-assertion disable, next to the existing one.
State the end-user limits once, in README § Caveats: a member colliding
with its stringification, the unsupported symbol/bigint, and NaN/-0. Drop
the duplicated known-issue prose from development/library.md and the
source comment; link to the README instead.
Drop the fixed no-floating-promises header exception from CONTRIBUTING.md
and AGENTS.md; agents must not add a source disable or edit .oxlintrc.json.
Record the split in tooling.md and testing.md: a one-site false positive is a
source disable, a file-class one lives in the test override.
The no-floating-promises header was repeated at the top of every test
file. Centralize it, and the no-null suppression the new null/undefined
cases need, in the **/*.test.ts override.
Extend the matcher universe beyond string | number so a union can carry
boolean, null and undefined members. true|false, null and undefined are
not property keys, so handler keys are their stringification while the
callback still receives the real member. Symbols are rejected (a brand
is compile-time only) and bigint is not a property key.
A fallback paired with a handler map that already covers `T` was still
accepted, even though its remainder is empty. Fold the guard into
`Handled`'s own (F-bounded) constraint so it is checked after inference;
a conditional in the fallback parameter is evaluated while `Handled` is
still its constraint and rejects every partial map whose handler callbacks
need contextual typing.
Drop the leaf-task exception in AGENTS.md: a task without subtasks was implemented on the current branch, bypassing create:branch / create:finish. Every task now opens and closes a branch, so the clean-tree / current-main / green-baseline preconditions and the post-merge verify always apply.
Rewrite development/library.md around the new shape: the fallback is a second
argument (so it can receive the remainder), `R` needs an inference site in the
handler map, `Exact` restores the excess-property check, and the overload order
is load-bearing. Record this branch's rejected alternatives (single-object `_`,
currying, `this`/HKT, variance/`const`/`NoInfer`/brands) and the redundant-
fallback known issue. Add the changelog note and check off the backlog task.
An open universe (`getMatcher<string>()`) types its handler map as an index
signature, so a runtime map with fewer keys still satisfies the exhaustive
overload. Calling the matcher with a missing shape reaches the dispatch guard
and throws — no cast needed.
When a fallback argument is present, the second overload supplies the
contextual type, so the handler map popup offers optional keys (`a? b? c?`)
and handled keys stay optional (`b? c?`). The exhaustive one-argument popup
is unchanged. Covered for both factories.
The factory-contract test now also covers a fallback whose return does not
fit the common return of the handler map — a `number` handler with a
`string` fallback — which `getMatcherW` accepts as `number | string`.
The fallback overload could not infer `R` from the handlers: `R` appeared
only inside the `Exact` constraint, which is not an inference site, so with
inferred handler params it collapsed to `unknown` and the matcher silently
returned `UnaryFn<T, unknown>`. Adding `Partial<Handlers<T, R>>` to the
handler parameter gives `R` an inference site, so the common return is
inferred from the handlers and the fallback alike.
Tests drop their explicit handler return annotations: real handlers are short
and unannotated, and the common type is now inferred from them.
The fallback is now the second factory argument — `(handlers, (s) => …)` —
so its parameter is `Exclude<T, keyof handlers>`. A property's contextual
type is fixed before TypeScript infers its sibling keys, so the remainder is
not expressible while the fallback sits in the handler map; a later argument
is contextually typed from inference on an earlier one.
Both factories take the new shape; the tests and autocomplete probes follow.
The generic overloads guard excess keys with type-fest's `Exact`, so the
error lands on the offending property. A redundant fallback (a full handler
map plus one) is still accepted — the guard for it does not survive inference
and is left to its backlog task.
The protocol cross-link and the TS-internal shutdown-race explanation were
too detailed for the category doc. The helper comment keeps a short,
self-contained note on the stdin-EOF workaround.
The completion helper is test-only (excluded from dist/), so the
style-only no-magic-numbers and unicorn/no-null warnings are tolerable
here. A file-level disable keeps them out of check:oxlint without touching
the project config.
The TS 7 Go server races Session.updateWatches against the exit
notification; handleExit returns io.EOF, the background context is
cancelled, and the bare error is flushed to stderr once the outgoing
queue closes (server.go / logger.go). Send shutdown and close stdin
instead: EOF makes the server exit cleanly (code 0, no output), with the
kill kept as a fallback. testing.md records the cause.
Note that the autocomplete helper drives the server through
vscode-languageserver-protocol, cross-link the tooling decision, and replace
the obsolete string-id known issue with the benign context-canceled stderr
the Go server emits on shutdown.
Replace the hand-rolled JSON-RPC client (framing, pending map, reply
dispatch) with createMessageConnection and typed requests from
vscode-languageserver-protocol. A catch-all onRequest answers the server
requests the old client replied to, and CompletionList/CompletionItem
replace the ad-hoc shape guards. Public LspSession API is unchanged.
The autocomplete helper drives tsc --lsp --stdio; vscode-languageserver-protocol
supplies the transport (re-exported vscode-jsonrpc/node) and the typed LSP
requests, replacing the hand-rolled JSON-RPC client. Record the choice and
the rejected alternatives in tooling.md.
The autocomplete helper still carries a hand-rolled JSON-RPC client
(Content-Length framing, a pending-request map, server-request replies).
vscode-languageserver-protocol provides all of it plus typed requests, so
track the move as a task with subtasks.
No tests live under scripts/, and every test script (test, test:unit, test:ci,
watch:test) globs only src/**/*.test.ts, so state that. The scripts/**
oxlint scope it was confused with still exists and carries the same
import/no-nodejs-modules exception as the test-helper scope.
Drop the strict/widened aliases from src/index.ts so the factories are
exported under their own names, and align the type tests, the autocomplete
probe (which now imports the public surface from ./index.ts) and library.md
with them.
Also correct the widened-overload comment: the excess-property check does not
apply to a generic P, so MatcherWidening's keyof guard — not the closed
constraint — is what rejects keys outside T/_, as library.md already
documented.
The matcher is now two three-overload factories; library.md documents why
the union merge, inferred universe, conditional RequireKeys and cases-first
paths were rejected, and lists the two open issues (the fallback sees all of
T; a redundant _ is still accepted). testing.md records the language server
as the autocomplete oracle, and CONTRIBUTING points the exception at the
matcher's own test file.
The backlog marks the design-doc and autocomplete groundwork done alongside
the adoption.
The helper's own contract — marker handling, requested position, label
extraction and the rejection when the marker is absent — is asserted against
in-memory documents whose contextual types are written inline, so the helper
is tested without coupling to the library's code.
strict/widened each take the exhaustive/fallback pattern shape in three
overloads ordered ExhaustiveLoose -> Fallback -> Handlers. TypeScript reads
the first overload for the object-literal popup (_?, a, b) and the last for
the missing-key error, so autocomplete and the error message are tuned
independently. The fallback is a pattern shape, not a factory, so the four
getPrimitiveUnionMatcher* factories collapse to two.
src/index.ts re-exports the two factories; the prototype scratch files that
explored the alternatives are removed.
Agents may add the fixed file-level typescript/no-floating-promises
oxlint-disable header at the top of a `*.test.ts` file — the
expectTypeOf() misidentification is a documented false positive
(development/testing.md § Known issues) and the await/void workarounds
collide with eslint/no-void. Every other suppression stays the human
last resort it was.
tmu