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.
development/testing.md § Test helpers: why name beats path under
import/no-relative-parent-imports, why the key needs `#`, why the
`__tests__` folder name, and what was rejected (flat placement, tsconfig
paths, rule exemptions).
src/util/__tests__/ holds shared test helpers, reached from anywhere
in the source tree as `#test-utils/<name>.ts` through
package.json#imports. A bare `~/…` is not a valid imports key — Node
requires `#` — and a direction-free specifier keeps
import/no-relative-parent-imports from ever firing. The `__tests__`
folder name is the pattern tsconfig.build.json already excludes, so
helpers can never ship. Lint scoping: import/no-nodejs-modules off for
the folder (the probe spawns a language server) and
typescript/promise-function-async off to match its promise-returning
style. The LSP probe moves in from scripts/; a smoke test pins the
specifier's resolution and typing without starting a server.
The example-code removal stripped the synopsis and examples with the
template modules; track bringing them back around the real API, with the
previous section order recorded so its placement is not re-guessed.
They were the template's demo API, not the library's real surface. Drop
them, their README walkthrough, and the tooling note that cited their
disable directives, and point index.ts at the primitive matchers that
remain.
The spec only exercised the template's match/P example API. Removing it
first lets the modules and exports it imports go next without leaving a
dangling reference.
Turn off `eslint/no-ternary` and `eslint/capitalized-comments` in the
project config: both encode a style the project rejects, so they belong in
the config's rule map rather than a per-site disable.
Scope the adjacent `oxlint-disable` decision to false positives and
record why a rejected stylistic rule is turned off project-wide.
Rewriting without any was evaluated; the alternatives were more
complex than the current solution. Record the rationale next to the
two oxlint-disable sites so the suppression is not re-litigated.
The primitive union matchers invoke every handler with the matched
literal, but the specs wrote their handlers with zero parameters, so
the passed value and its inferred key-literal type went untested.
Declare the parameter on each such handler and pin it with
expectTypeOf, matching the style the two already-correct handlers used.
The `_` fallbacks assert the whole union rather than a single literal.
Return-type expectations are unchanged, so the W / non-W widening
distinctions are still covered.
getPrimitiveUnionMatcherPartialW was declared with the intended
P-inferring signature but assigned via `as any`, hiding that the
declared parameter was not assignable to the implementation's. The
union in PatternPrimitiveUnionPartial makes the `_` arm demand
`_ ∈ keyof P`, which the exhaustive arm cannot prove.
Intersect the inference hook Simplify<P> with the implementation's
parameter shape, R pinned to PatternReturns<P>, so the assignment
type-checks while callers keep inferring P from the argument.
Add a spec for the exhaustive (no `_`) pattern.
launch.json: 'Debug current test file' F5 config running
node --test --strip-types on the active file.
settings.json: register .ts with the connor4312.nodejs-testing
extension via nodejs-testing.extensions, using --strip-types (the
repo pins node >=26 with native type stripping) instead of tsx, so
the extension discovers src/*.test.ts and shows Run/Debug lenses
above test() calls in the native Testing UI.
extensions.json: recommend connor4312.nodejs-testing; cspell.json:
allow 'connor' for the extension id.
.gitignore: un-ignore .vscode/launch.json so the config is shared.
Rework every test body into // Arrange / // Act / // Assert blocks
separated by blank lines: the factory is arranged once, the matcher is
built from it in a single act, and all type/runtime checks sink to the
end. index.test.ts adopts the same shape.
Also migrate off expect-type's deprecated toMatchTypeOf: the checks
are assignability tests, so toExtend is the faithful replacement.
Type-driven tests: every expectTypeOf pairs an assert, covering the
header matrix (exhaustive vs partial patterns, strict R vs widened
returns, string and numeric keys, _ fallback wiring).
Negative cases use Parameters<typeof factory>[0] assignability because
expect-type's .not.toBeCallableWith collapses to never on these generic
Simplify<>-wrapped signatures.
Same documented expectTypeOf floating-promise false positive as
index.test.ts, so the same file-level disable applies; testing.md
known-issue updated to list both files.
Curried matchers over string|number literal unions in four variants
(exhaustive/partial x strict/widened return inference), per the header
matrix in src/primitive.ts.
- Adds type-fest for Simplify/ValueOf.
- Deliberate oxlint escape hatches (as any dispatch) until a cast-free
formulation lands; see the file comments.
Actionable sentence in CONTRIBUTING.md § Rules the tools don't enforce;
the why — humans skim, agents imitate the dominant style, so verbosity
compounds — in development/README.md § Decision blocks. Both sides in
one commit per the write-each-fact-once rule.
DefinitelyTyped keeps the @types/node latest dist-tag on the LTS line,
so check-outdated compared the current-line types against a lower
version: a permanent "reverted" flag, scan exit 1, zero signal. Ignored
by package name; --types filtering and a version-scoped pin rejected
(rationale in development/tooling.md).
@types/node to ^26.6.1 and cspell to ^10.3.2 — the only packages
check-outdated found behind the registry, both bumps within the existing
semver ranges. cspell 10.3.2 drops its transitive
fast-json-stable-stringify. npm run verify is green with no rule or
format fallout. maintain:outdated still flags @types/node as "reverted"
because DefinitelyTyped's latest dist-tag stays on the 22.x LTS series;
known false positive, advisory scan only.
`create:finish` leaves the merge local until `create:release` pushes it, so
`main` is routinely ahead of its upstream between a merge and a release. The
branch front door demanded an exact match and refused until it was pushed,
forcing a manual `git push` that the model deliberately keeps out of it.
Reject only a `main` that is behind its upstream — matching `create:finish`,
which already tolerates being ahead — and record why pushing from `finish` was
rejected instead. The push stays with `create:release`, so the merge remains
reviewable locally, and the known issue about the deadlock is gone.
Resolves: backlog task "Resolve the finish/push tension".
A merged branch must carry a final commit adding a short summary of the
work under [Unreleased] in CHANGELOG.md. create:release derives the bump
heuristic from that body, so notes have to exist before release day;
rationale in development/workflow.md.
tmu