fix(opencode): make the declined-hooks plugin stub satisfy the V2 loader schema

The inert stub written when hook consent is not granted was
`export default async () => ({})`. OpenCode v2 validates every plugin
module before running it and requires the default export to be a definition
object with an `id` and an `effect` or `setup` function, so a declined or
runtime-less home install printed the same startup error as the V1 hook
plugin:

  PluginModule.LoadError: Plugin must export a default definition with an id
  and an effect or setup function.
  (cause: SchemaError(Expected object at ["default"]))

Write `export default { id: "ecc-hooks", setup() {} }` instead. It keeps the
inert behaviour (no imports, no module initialization of the replaced
plugin) and satisfies the loader.

Tests that pinned the generated bytes now compare against
getDisabledOpenCodePluginContent() rather than a duplicated literal, and
tests/opencode-plugin-loader-contract.test.js asserts the loader contract on
the generated payload. That test fails on the previous stub
("default export must be an object, got function").

Refs #3537. The same assertion should cover .opencode/plugins/*.ts once a V2
entrypoint lands (#3536, #3224); those plugins are scanned independently in
home installs, so both the barrel and the implementation are loaded.

scripts/lib/install/hook-consent.js

@@ -183,7 +183,12 @@ function isOpenCodePluginEntrypoint(operation = {}) {
 function getDisabledOpenCodePluginContent() {
   // OpenCode discovers plugins independently of opencode.json registration.
   // Do not import the original module: even module initialization has effects.
-  return 'export default async () => ({});\n';
+  // The stub must still satisfy the V2 loader schema: the default export has to
+  // be a definition object with an id and an effect or setup function. A factory
+  // (`export default async () => ({})`) is rejected at startup with
+  // PluginModule.LoadError / SchemaError(Expected object at ["default"]), which
+  // is the same failure reported for the V1 hook plugin in issue #3537.
+  return 'export default { id: "ecc-hooks", setup() {} };\n';
 }
 
 function isOpenCodeHookActivationOperation(operation = {}) {

tests/lib/install-executor.test.js

@@ -22,7 +22,7 @@ const {
 const { applyInstallPlan: applyInstallPlanDirect } = require('../../scripts/lib/install/apply');
 const { normalizeInstallRequest } = require('../../scripts/lib/install/request');
 const { createInstallPlanFromRequest } = require('../../scripts/lib/install/runtime');
-const { withHookConsent } = require('../../scripts/lib/install/hook-consent');
+const { getDisabledOpenCodePluginContent, withHookConsent } = require('../../scripts/lib/install/hook-consent');
 const { repairInstalledStates, uninstallInstalledStates } = require('../../scripts/lib/install-lifecycle');
 
 const REPO_ROOT = path.resolve(__dirname, '..', '..');
@@ -53,7 +53,7 @@ function operationFor(plan, suffix) {
   ));
 }
 
-const INERT_OPENCODE_PLUGIN = 'export default async () => ({});\n';
+const INERT_OPENCODE_PLUGIN = getDisabledOpenCodePluginContent();
 const OPENCODE_ENTRYPOINTS = ['ecc-hooks.ts', 'index.ts'];
 
 function snapshotFiles(root) {

tests/lib/install-lifecycle.test.js

@@ -29,6 +29,7 @@ const {
   materializeManagedHooks,
 } = require('../../scripts/lib/install/claude-settings');
 const { readHooksConfig } = require('../../scripts/lib/hooks-config');
+const { getDisabledOpenCodePluginContent } = require('../../scripts/lib/install/hook-consent');
 
 const REPO_ROOT = path.join(__dirname, '..', '..');
 const CURRENT_PACKAGE_VERSION = JSON.parse(
@@ -2048,7 +2049,7 @@ function runTests() {
         applyInstallPlan(plan);
         const pluginPaths = ['ecc-hooks.ts', 'index.ts'].map(name => path.join(plan.targetRoot, 'plugins', name));
         for (const pluginPath of pluginPaths) {
-          assert.strictEqual(fs.readFileSync(pluginPath, 'utf8'), 'export default async () => ({});\n');
+          assert.strictEqual(fs.readFileSync(pluginPath, 'utf8'), getDisabledOpenCodePluginContent());
           fs.unlinkSync(pluginPath);
         }
         const before = buildDoctorReport({ repoRoot: REPO_ROOT, homeDir, projectRoot: homeDir, targets: ['opencode'] });
@@ -2067,7 +2068,7 @@ function runTests() {
         assert.strictEqual(buildCalls, 1, 'Only the injected inert builder is used');
         assert.strictEqual(repaired.results[0].status, 'repaired');
         for (const pluginPath of pluginPaths) {
-          assert.strictEqual(fs.readFileSync(pluginPath, 'utf8'), 'export default async () => ({});\n');
+          assert.strictEqual(fs.readFileSync(pluginPath, 'utf8'), getDisabledOpenCodePluginContent());
         }
         const state = readInstallState(plan.installStatePath);
         assert.strictEqual(state.request.hookConsent, 'declined');
@@ -2101,7 +2102,7 @@ function runTests() {
         });
         assert.strictEqual(result.results[0].status, 'repaired');
         for (const name of ['ecc-hooks.ts', 'index.ts']) {
-          assert.strictEqual(fs.readFileSync(path.join(recorded.targetRoot, 'plugins', name), 'utf8'), 'export default async () => ({});\n');
+          assert.strictEqual(fs.readFileSync(path.join(recorded.targetRoot, 'plugins', name), 'utf8'), getDisabledOpenCodePluginContent());
         }
         assert.ok(!JSON.parse(fs.readFileSync(path.join(recorded.targetRoot, 'opencode.json'), 'utf8')).plugin.includes('./plugins'));
         const state = readInstallState(recorded.installStatePath);

tests/lib/opencode-consent-legacy-lock.test.js

@@ -11,7 +11,7 @@ const { assertFilePostimage } = require('./helpers/assert-file-postimage');
 const fileSystem = { ...fs };
 const load = createFileSystemLoader(fileSystem);
 const { applyInstallPlan } = load(require.resolve('../../scripts/lib/install/apply'));
-const { withHookConsent } = require('../../scripts/lib/install/hook-consent');
+const { getDisabledOpenCodePluginContent, withHookConsent } = require('../../scripts/lib/install/hook-consent');
 const { repairInstalledStates, buildDoctorReport } = load(require.resolve('../../scripts/lib/install-lifecycle'));
 const { createInstallState, readInstallState, writeInstallState } = require('../../scripts/lib/install-state');
 const { withOpenCodeInstallLocks } = load(require.resolve('../../scripts/lib/install/opencode-install-lock'));
@@ -325,7 +325,7 @@ function runTests() {
       assert.ok(!state.resolution.selectedModules.includes('hooks-runtime'));
       assert.notStrictEqual(state.request.hookConsent, 'enabled');
       assert.strictEqual(fs.readFileSync(path.join(value.canonicalRoot, 'plugins/ecc-hooks.ts'), 'utf8'),
-        'export default async () => ({});\n');
+        getDisabledOpenCodePluginContent());
       assert.deepStrictEqual(JSON.parse(fs.readFileSync(path.join(value.canonicalRoot, 'opencode.json'))).plugin, []);
       for (const relative of ['opencode.json', 'plugins/ecc-hooks.ts', 'ecc-install-state.json']) {
         assert.strictEqual(fs.existsSync(path.join(value.legacyRoot, relative)), false);

tests/lib/opencode-hook-consent-safety.test.js

@@ -9,7 +9,11 @@ const { createFileSystemLoader } = require('./helpers/load-with-file-system');
 const fileSystem = { ...fs };
 const load = createFileSystemLoader(fileSystem);
 const { applyInstallPlan } = load(require.resolve('../../scripts/lib/install/apply'));
-const { parseJsoncConfig, withHookConsent } = require('../../scripts/lib/install/hook-consent');
+const {
+  getDisabledOpenCodePluginContent,
+  parseJsoncConfig,
+  withHookConsent,
+} = require('../../scripts/lib/install/hook-consent');
 const { createInstallState, readInstallState, writeInstallState } = require('../../scripts/lib/install-state');
 const { buildDoctorReport, repairInstalledStates } = load(require.resolve('../../scripts/lib/install-lifecycle'));
 
@@ -326,7 +330,7 @@ function runTests() {
     assert.strictEqual(result.status, 'repaired', result.error);
     assert.strictEqual(result.stateRefreshed, true);
     assert.strictEqual(fs.readFileSync(path.join(value.targetRoot, 'plugins/ecc-hooks.ts'), 'utf8'),
-      'export default async () => ({});\n');
+      getDisabledOpenCodePluginContent());
     assert.deepStrictEqual(JSON.parse(fs.readFileSync(path.join(value.targetRoot, 'opencode.json'))),
       { plugin: [], userSetting: true });
     assert.strictEqual(fs.existsSync(`${value.installStatePath}.ecc.lock`), false);
@@ -348,7 +352,7 @@ function runTests() {
           assert.ok(!operations.some(operation => operation.destinationPath === destination), 'Do not adopt a user config');
         }
         assert.strictEqual(fs.readFileSync(path.join(value.targetRoot, 'plugins/ecc-hooks.ts'), 'utf8'),
-          'export default async () => ({});\n');
+          getDisabledOpenCodePluginContent());
         assert.strictEqual(fs.existsSync(`${value.installStatePath}.ecc.lock`), false);
       }));
     }
@@ -446,7 +450,7 @@ function runTests() {
       // must never adopt the preserved user config after this refusal.
       const checkpoint = readInstallState(value.installStatePath);
       assert.deepStrictEqual(checkpoint.operations.map(operation => operation.destinationPath), [plugin]);
-      assert.strictEqual(fs.readFileSync(plugin, 'utf8'), 'export default async () => ({});\n');
+      assert.strictEqual(fs.readFileSync(plugin, 'utf8'), getDisabledOpenCodePluginContent());
       assert.strictEqual(checkpoint.operations[0].contentSha256, sha256(fs.readFileSync(plugin)));
       assert.strictEqual(fs.existsSync(`${value.installStatePath}.ecc.lock`), false);
     }));
@@ -629,7 +633,7 @@ function runTests() {
         operations: [...value.basePlan.operations, operation] }, consent);
       assert.strictEqual(applyInstallPlan(plan).applied, true);
       assert.strictEqual(fs.readFileSync(destinationPath, 'utf8'), consent === 'enabled'
-        ? content : 'export default async () => ({});\n');
+        ? content : getDisabledOpenCodePluginContent());
     }));
   }
   test('nested package metadata fails before writing and never receives a JavaScript tombstone', () => fixture(value => {

tests/opencode-plugin-loader-contract.test.js

@@ -0,0 +1,100 @@
+/**
+ * Tests for the OpenCode V2 plugin loader contract.
+ *
+ * OpenCode v2 validates every plugin module before running it: the default export
+ * must be an object with an `id` and an `effect` or `setup` function
+ * (packages/core/src/plugin/module.ts). A factory default export, which is what a
+ * V1 plugin used, fails at startup with
+ *
+ *   PluginModule.LoadError: Plugin must export a default definition with an id and
+ *   an effect or setup function. (cause: SchemaError(Expected object at ["default"]))
+ *
+ * so a declined-hooks install still printed the same error as the V1 plugin did
+ * (issue #3537). These tests pin the contract on the payload ECC generates itself.
+ *
+ * Run with: node tests/opencode-plugin-loader-contract.test.js
+ */
+
+const assert = require('assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const { pathToFileURL } = require('url');
+
+const { getDisabledOpenCodePluginContent } = require('../scripts/lib/install/hook-consent');
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  ✓ ${name}`);
+    return true;
+  } catch (err) {
+    console.log(`  ✗ ${name}`);
+    console.log(`    Error: ${err.message}`);
+    return false;
+  }
+}
+
+/** Loads generated plugin source the way the OpenCode loader does: import it. */
+async function loadPluginModule(source) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-plugin-contract-'));
+  const file = path.join(dir, 'plugin.mjs');
+  fs.writeFileSync(file, source);
+  return import(pathToFileURL(file).href);
+}
+
+/** Mirrors the loader schema: { default: { id, effect } | { id, setup } }. */
+function assertV2PluginDefinition(namespace, label) {
+  const definition = namespace.default;
+  assert.ok(
+    definition && typeof definition === 'object',
+    `${label}: default export must be an object, got ${typeof definition}`
+  );
+  assert.strictEqual(typeof definition.id, 'string', `${label}: default export needs a string id`);
+  assert.ok(
+    typeof definition.effect === 'function' || typeof definition.setup === 'function',
+    `${label}: default export needs an effect or setup function`
+  );
+}
+
+async function main() {
+  let passed = 0;
+  let failed = 0;
+
+  const check = async (name, fn) => {
+    try {
+      await fn();
+      console.log(`  ✓ ${name}`);
+      passed += 1;
+    } catch (err) {
+      console.log(`  ✗ ${name}`);
+      console.log(`    Error: ${err.message}`);
+      failed += 1;
+    }
+  };
+
+  const stub = getDisabledOpenCodePluginContent();
+  const stubModule = await loadPluginModule(stub);
+
+  await check('declined-hooks stub satisfies the V2 loader schema', () => {
+    assertV2PluginDefinition(stubModule, 'disabled OpenCode plugin stub');
+  });
+
+  await check('the stub check still rejects a V1 factory default export', async () => {
+    const v1 = await loadPluginModule('export default async () => ({});\n');
+    assert.throws(() => assertV2PluginDefinition(v1, 'V1 factory'), /default export must be an object/);
+  });
+
+  await check('the stub does not import the module it replaces', () => {
+    assert.ok(!/^\s*import\s/m.test(stub), 'stub must stay free of imports');
+  });
+
+  // The same check applies to every shipped plugin entrypoint once a V2 entrypoint
+  // lands (.opencode/plugins/*.ts is scanned independently in home installs).
+  // See issue #3537 and the API ports in #3536 and #3224.
+
+  console.log(`\n  ${passed} passed, ${failed} failed\n`);
+  process.exit(failed === 0 ? 0 : 1);
+}
+
+main();