feat(gstack2): add unified execution result contract

test/gstack2-runtime-effect-cli.test.ts

@@ -95,4 +95,23 @@ describe('gstack state external-effect CLI', () => {
       { cwd, env, stdout: out, stderr: err },
     )).toBe(2);
   });
+
+  test('an empty exit-zero tool result is uncertain, never successful', async () => {
+    const { cwd, env } = await fixture();
+    const out = sink();
+    const err = sink();
+    await main(['state', 'begin', 'ship', '--run-id', 'run_empty'], { cwd, env, stdout: out, stderr: err });
+    const silent = path.join(cwd, 'silent.sh');
+    await fs.writeFile(silent, '#!/bin/sh\nexit 0\n', { mode: 0o755 });
+    const code = await main([
+      'state', 'effect', 'run_empty', 'silent.tool', '--', silent,
+    ], { cwd, env, stdout: out, stderr: err });
+    expect(code).toBe(1);
+    expect(err.value()).toContain('may have occurred');
+    expect(out.value()).not.toContain('"status":"success"');
+    expect(await main([
+      'state', 'effect', 'run_empty', 'silent.tool', '--', silent,
+    ], { cwd, env, stdout: out, stderr: err })).toBe(1);
+    expect(err.value()).toContain('was already claimed');
+  });
 });

test/gstack2-runtime-execution-result.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, test } from "bun:test";
+import {
+  EXECUTION_RESULT_ERROR_CODES,
+  executionResult,
+  renderExecutionResult,
+  validateExecutionResult,
+} from "../runtime/execution-result.js";
+
+describe("GStack execution-result contract", () => {
+  test("accepts evidenced success and preserves it in both renderings", () => {
+    const result = executionResult({ status: "success", summary: "Probe completed", evidence: ["exit code 0"], data: { count: 1 } });
+    expect(JSON.parse(renderExecutionResult(result, { json: true }))).toEqual(result);
+    expect(renderExecutionResult(result)).toContain("SUCCESS: Probe completed");
+  });
+
+  test("rejects empty and malformed values instead of inferring success", () => {
+    expect(() => validateExecutionResult(null)).toThrow();
+    expect(() => executionResult({ status: "success", summary: "Done", evidence: [], data: null }))
+      .toThrow("requires evidence");
+    try {
+      executionResult({ status: "success", summary: "Done", evidence: [], data: null });
+    } catch (error: any) {
+      expect(error.code).toBe(EXECUTION_RESULT_ERROR_CODES.EMPTY);
+    }
+  });
+
+  test.each([
+    ["degraded", "EXECUTION_DEGRADED"],
+    ["unsupported", "EXECUTION_UNSUPPORTED"],
+    ["failed", "EXECUTION_FAILED"],
+  ])("keeps %s explicitly non-success", (status, code) => {
+    const result = executionResult({ status, code, summary: `${status} result`, evidence: [], data: null });
+    expect(renderExecutionResult(result)).toStartWith(`${status.toUpperCase()} [${code}]`);
+  });
+});

test/gstack2-skill-ux.test.ts

@@ -62,8 +62,11 @@ describe('GStack 2 canonical skill UX', () => {
       const runtime = fs.readFileSync(path.join(ROOT, 'skills', tree, 'references', 'RUNTIME.md'), 'utf8');
       const bootstrap = fs.readFileSync(path.join(ROOT, 'skills', tree, 'references', 'support', 'runtime-bootstrap.mjs'));
       const contract = JSON.parse(fs.readFileSync(path.join(ROOT, 'skills', tree, 'references', 'support', 'runtime-contract.json'), 'utf8'));
+      const resultContract = JSON.parse(fs.readFileSync(path.join(ROOT, 'skills', tree, 'references', 'support', 'execution-result-contract.json'), 'utf8'));
       expect(bootstrap, tree).toEqual(source);
       expect(contract, tree).toEqual({ schemaVersion: 1, runtimeVersion: '2.0.0', skillApi: '2.0' });
+      expect(resultContract.properties.status.enum, tree).toEqual(['success', 'degraded', 'unsupported', 'failed']);
+      expect(resultContract.allOf[0].then.properties.evidence.minItems, tree).toBe(1);
       expect(runtime, tree).toContain('preview --capability <name>');
       expect(runtime, tree).toContain('It never downloads components or mutates runtime state.');
       expect(runtime, tree).toContain('install --capability <name> --yes');