fix: address all seven final-gate findings for typed api blocks

B1: qualify each generated __wrn_api_check_* assertion name with a short
hash of the page's path (relative to app/, for reproducibility across
checkouts) so two pages declaring a same-named block no longer collide
with an identical type alias (TS2300).

B2: skip assertion emission for any block that is not client-mode, or
that has zero declared request fields. ssr sectioned blocks can never
declare a request and always fell back to Record<string, never>, whose
keyof is `string` -- making the key-exactness arm of AssertAssignable
evaluate to false unconditionally (TS2344) on every ssr sectioned block
regardless of correctness. Chose to skip both non-client blocks and
zero-field client blocks, since neither has anything meaningful to
assert type-safety about.

B3: only resolve the endpoint's input (query params / ctx.req.json())
when the endpoint declares an input schema. Previously the router-set
fix accidentally read the request body unconditionally, so a handler
with no input schema that parses the request itself hit
ERR_BODY_ALREADY_USED.

B4: run response/error bodies in client-mode api blocks through
eraseFunctionTypes, matching every other browser-bound body in
client-codegen.ts, so a TypeScript-only construct inside one (e.g. an
annotated locally-declared function) doesn't reach the .mjs artifact.

B5: only exclude "api" from state/prop destructuring in the generated
browser module when the page actually has client-mode api blocks (i.e.
there is a real `api` binding to shadow). Previously "api" was always
excluded, so a page with `state api` and no api blocks got an
undeclared `api` reference (ReferenceError) in client code.

B6: prefix each emitted assertion with `export`, so it isn't flagged as
an unused local under a downstream project's noUnusedLocals (TS6196).

B7: wrnexusCallApi now resolves with undefined for an ok 204/205
response, or an ok response with an empty/unparseable body, instead of
rejecting with "Response was not valid JSON" -- matching the spec's
failure table (error path only for non-2xx, network failure, or an
actually unparseable body on a non-empty response).

Regenerated examples/basic-app's generated types and editor bundles to
match. Confirmed the example's type gate still fails when an
unaccepted field is added to a request body, and passes cleanly
otherwise.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/cli/src/types.ts

@@ -106,26 +106,62 @@ function writePluginArtifacts(root: string, contributions?: PluginContributions)
  * `app/` and is therefore compiled by the project's own tsc, while generated
  * build artifacts are not type-checked at all.
  */
-function apiBlockAssertions(pages: { path: string; ast: PageAst }[], apiContracts: string): string {
+function pageSlug(path: string): string {
+  // Block names are only unique within a single page (see apiBindingMap), so
+  // two pages each declaring e.g. `api search` is legal and would otherwise
+  // emit the identical `__wrn_api_check_search` type alias twice into this
+  // one flat file — TS2300 ("duplicate identifier"). Qualify every emitted
+  // name with a short deterministic hash of the page's path (not the whole
+  // path itself, which can be arbitrarily long/ugly once made identifier-safe)
+  // to keep names unique across the whole app while staying compact.
+  const normalized = path.replace(/\\/g, "/");
+  let hash = 0;
+  for (let i = 0; i < normalized.length; i++) {
+    hash = (Math.imul(hash, 31) + normalized.charCodeAt(i)) | 0;
+  }
+  return (hash >>> 0).toString(36);
+}
+
+function apiBlockAssertions(
+  pages: { path: string; ast: PageAst }[],
+  apiContracts: string,
+  appDir: string,
+): string {
   const lines: string[] = [];
 
   for (const page of pages) {
+    // Hash the path relative to `app/`, not the absolute path: the absolute
+    // path varies with where the project checkout lives (e.g. a CI runner's
+    // temp clone vs. a developer's local path), which would make this file
+    // spuriously "stale" every time it's regenerated somewhere else.
+    const slug = pageSlug(relative(appDir, page.path).replace(/\\/g, "/"));
     for (const block of page.ast.dataApis) {
       if (!block.sections) continue;
 
+      // ssr-mode sectioned blocks can never declare a `request` (they are
+      // render-time only), so they always fall back to the empty-shape
+      // `Record<string, never>` below. `keyof Record<string, never>` is
+      // `string`, which makes the key-exactness arm of AssertAssignable
+      // evaluate to `false` unconditionally and raises TS2344 on every such
+      // block regardless of whether the block author did anything wrong.
+      // We choose to skip emission for both (a) any non-client-mode block,
+      // since it structurally can never have a request to check, and (b) any
+      // block -- client included -- that has zero declared request fields,
+      // since there is nothing to assert type-safety about. This is more
+      // honest about intent than emitting a vacuous/always-failing check.
+      const fields = [...block.sections.parameters, ...block.sections.body];
+      if (block.mode !== "client" || fields.length === 0) continue;
+
       if (!apiContracts.includes(JSON.stringify(block.path))) {
         console.warn(
           `[wrnexus] api block "${block.name}" targets ${block.path}, which has no defineEndpoint contract — its declared types are not checked.`,
         );
       }
 
-      const fields = [...block.sections.parameters, ...block.sections.body];
-      const shape = fields.length
-        ? `{ ${fields.map((f) => `${f.name}${f.optional ? "?" : ""}: ${f.type}`).join("; ")} }`
-        : "Record<string, never>";
+      const shape = `{ ${fields.map((f) => `${f.name}${f.optional ? "?" : ""}: ${f.type}`).join("; ")} }`;
 
       lines.push(
-        `type __wrn_api_check_${block.name} = WRNexusGenerated.__wrn_expect_true<WRNexusGenerated.AssertAssignable<${shape}, WRNexusGenerated.ApiInput<${JSON.stringify(
+        `export type __wrn_api_check_${slug}_${block.name} = WRNexusGenerated.__wrn_expect_true<WRNexusGenerated.AssertAssignable<${shape}, WRNexusGenerated.ApiInput<${JSON.stringify(
           block.path,
         )}, ${JSON.stringify(block.method)}>>>;`,
       );
@@ -281,7 +317,7 @@ declare namespace WRNexusGenerated {
 // Type-only assertions for sectioned \`api\` blocks. Kept as a real .ts file (not
 // wrnexus.generated.d.ts) because \`skipLibCheck\` exempts .d.ts contents from being
 // checked; this file is compiled and checked normally by the project's own tsc.
-${apiBlockAssertions(pageAsts, apiContracts)}
+${apiBlockAssertions(pageAsts, apiContracts, app)}
 export {};
 `;
   writeFileSync(join(typeDir, "wrnexus.generated.api-checks.ts"), apiChecksCode, "utf8");