fix(cli): drop the never-produced dist/index.cjs requirement from prepublish's opencode-plugin skip check (#11787)

changelog.d/fixes/11787-prepublish-opencode-plugin-cjs-check.md

@@ -0,0 +1 @@
+- fix(cli): stop prepublish from re-rebuilding the already-built ESM-only opencode-plugin dist (#11787)

scripts/build/prepublish.ts

@@ -483,9 +483,11 @@ if (existsSync(cliSrcFile)) {
 // flow for every downstream user.
 const opencodePluginSrc = join(ROOT, "@omniroute", "opencode-plugin");
 const opencodePluginDist = join(opencodePluginSrc, "dist", "index.js");
-const opencodePluginCjs = join(opencodePluginSrc, "dist", "index.cjs");
 if (existsSync(opencodePluginSrc) && existsSync(join(opencodePluginSrc, "package.json"))) {
-  const pluginAlreadyBuilt = existsSync(opencodePluginDist) && existsSync(opencodePluginCjs);
+  // The plugin's tsup config is ESM-only (format: ["esm"]), so a successful
+  // build only ever produces dist/index.js (+ dist/index.d.ts) — never
+  // dist/index.cjs. Gate the skip solely on dist/index.js.
+  const pluginAlreadyBuilt = existsSync(opencodePluginDist);
   if (!pluginAlreadyBuilt) {
     console.log("\n  🔨 Building @omniroute/opencode-plugin (tsup)...");
     try {

tests/unit/prepublish-opencode-plugin-build-skip.test.ts

@@ -0,0 +1,95 @@
+// Regression test for issue #11787.
+//
+// scripts/build/prepublish.ts gates the "@omniroute/opencode-plugin already
+// built -> skip rebuild" fast path on both dist/index.js AND dist/index.cjs
+// existing. @omniroute/opencode-plugin/tsup.config.ts is ESM-only
+// (format: ["esm"]), so a successful `tsup` run in that package never
+// produces dist/index.cjs -- the old predicate could never be true.
+//
+// This test builds the REAL plugin package with the REAL tsup config (no
+// mocks) and then evaluates the fixed predicate copied from prepublish.ts
+// against the resulting dist/, proving the "already built" skip path now
+// works for an ESM-only build, and still correctly reports "not built" when
+// dist/ is absent.
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { execFileSync } from "node:child_process";
+import { existsSync, rmSync } from "node:fs";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+import { resolveLocalBinEntry, isNativeExecutable } from "../../scripts/build/buildToolRunner.mjs";
+import { resolveBundledNpmEntry } from "../../scripts/build/resolveNpmEntry.ts";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const ROOT = join(__dirname, "..", "..");
+const opencodePluginSrc = join(ROOT, "@omniroute", "opencode-plugin");
+const opencodePluginDist = join(opencodePluginSrc, "dist", "index.js");
+const opencodePluginCjs = join(opencodePluginSrc, "dist", "index.cjs");
+
+test("prepublish pluginAlreadyBuilt predicate recognizes a real ESM-only tsup build (#11787)", () => {
+  rmSync(join(opencodePluginSrc, "dist"), { recursive: true, force: true });
+  // The plugin is a standalone package, not an npm workspace member (see
+  // scripts/build/prepublish.ts's own comment above the equivalent build step) — a
+  // root `npm ci` never populates its node_modules, so a fresh checkout (CI, or any
+  // devbox that hasn't built the plugin before) needs its own install first. Mirror
+  // prepublish.ts's own install step instead of hardcoding a `.bin/tsup` path that
+  // only exists on a devbox someone happened to `npm install` in already.
+  if (!existsSync(join(opencodePluginSrc, "node_modules"))) {
+    const npmEntry = resolveBundledNpmEntry("npm-cli.js");
+    const installArgs = ["install", "--no-audit", "--no-fund"];
+    if (npmEntry) {
+      execFileSync(process.execPath, [npmEntry, ...installArgs], {
+        cwd: opencodePluginSrc,
+        stdio: "inherit",
+      });
+    } else {
+      execFileSync("npm", installArgs, { cwd: opencodePluginSrc, stdio: "inherit" });
+    }
+  }
+  // Resolve the real tsup binary the same way scripts/build/prepublish.ts's
+  // runBuildTool() does — never a hardcoded `.bin/tsup` path, since npm's hoisting can
+  // place the binary at the plugin's own node_modules/.bin OR the repo root's,
+  // depending on the install.
+  const localEntry = resolveLocalBinEntry("tsup", "tsup", opencodePluginSrc);
+  if (localEntry) {
+    if (isNativeExecutable(localEntry)) {
+      execFileSync(localEntry, [], { cwd: opencodePluginSrc, stdio: "inherit" });
+    } else {
+      execFileSync(process.execPath, [localEntry], { cwd: opencodePluginSrc, stdio: "inherit" });
+    }
+  } else {
+    const npxEntry = resolveBundledNpmEntry("npx-cli.js");
+    if (npxEntry) {
+      execFileSync(process.execPath, [npxEntry, "tsup"], {
+        cwd: opencodePluginSrc,
+        stdio: "inherit",
+      });
+    } else {
+      execFileSync("npx", ["tsup"], { cwd: opencodePluginSrc, stdio: "inherit" });
+    }
+  }
+
+  assert.equal(existsSync(opencodePluginDist), true, "dist/index.js should exist after tsup");
+  assert.equal(
+    existsSync(opencodePluginCjs),
+    false,
+    "dist/index.cjs should NOT exist for an ESM-only tsup build"
+  );
+
+  // This is the fixed predicate from scripts/build/prepublish.ts.
+  const pluginAlreadyBuilt = existsSync(opencodePluginDist);
+
+  assert.equal(
+    pluginAlreadyBuilt,
+    true,
+    "expected the ESM-only build to be recognized as already built (index.js present is sufficient)"
+  );
+});
+
+test("prepublish pluginAlreadyBuilt predicate is false when dist/ is absent (#11787)", () => {
+  rmSync(join(opencodePluginSrc, "dist"), { recursive: true, force: true });
+
+  const pluginAlreadyBuilt = existsSync(opencodePluginDist);
+
+  assert.equal(pluginAlreadyBuilt, false, "expected a missing dist/ to require a rebuild");
+});