test(spec): type-check the spec api as part of make test

The fake runtime in api.test.ts did not return a chainable handle from extract,
so the file had not type-checked since named() was added. Wiring the check into
make test stops it drifting again.

Claude-Session: https://claude.ai/code/session_01Fj4wJUikdABuMQEETwW55J

Makefile

@@ -29,7 +29,7 @@ WEB_DIST := replay-ui/dist
 
 GOLINES := $(shell $(GO) env GOPATH)/bin/golines
 
-.PHONY: bootstrap proto sidecar sanderling install test test-go test-browser test-companion test-kotlin test-spec-api web-test web-typecheck web-build web-dev replay-dev docs clean release-cli release-npm-dry fmt fmt-go fmt-kotlin fmt-ts fmt-swift
+.PHONY: bootstrap proto sidecar sanderling install test test-go test-browser test-companion test-kotlin test-spec-api spec-typecheck web-test web-typecheck web-build web-dev replay-dev docs clean release-cli release-npm-dry fmt fmt-go fmt-kotlin fmt-ts fmt-swift
 
 bootstrap:
 	$(GO) mod download
@@ -101,7 +101,7 @@ fmt-ts:
 fmt-swift:
 	xcrun swift-format format -i -r companion/Sources
 
-test: test-go test-spec-api web-typecheck web-test
+test: test-go spec-typecheck test-spec-api web-typecheck web-test
 
 test-go:
 	$(GO) test $(GO_PACKAGES)
@@ -126,6 +126,9 @@ test-kotlin:
 test-spec-api:
 	cd pkg/spec && npm test --silent
 
+spec-typecheck:
+	cd pkg/spec && npm run check --silent
+
 docs: $(DOCS_OUT) build/site/_assets
 	@echo "built $(words $(DOCS_OUT)) pages to build/site"
 

pkg/spec/test/api.test.ts

@@ -112,7 +112,12 @@ function installFakeRuntime(): RecordedRuntime {
     extract: <T>(getter: (state: State) => T, name?: string): Extracted<T> => {
       calls.extracts.push(getter as (state: State) => unknown);
       calls.extractNames.push(name);
-      return { current: undefined as unknown as T, previous: undefined };
+      const handle: Extracted<T> = {
+        current: undefined as unknown as T,
+        previous: undefined,
+        named: () => handle,
+      };
+      return handle;
     },
     always: (predicateOrFormula: (() => boolean) | Formula): Formula => {
       calls.alwaysArgs.push(predicateOrFormula);