fix(#224): return byte counts for --pick stdout capture (#226)

tests/bug-1891-file-resolution.test.cjs

@@ -48,17 +48,14 @@ describe('bug #1891: @file: resolution in gsd-tools.cjs', () => {
   });
 
   test('stdout interception wraps runCommand in the non-pick path', () => {
-    // The main function should intercept fs.writeSync for fd=1
-    // in BOTH the pick path AND the normal path
+    // The main function should resolve @file: output in BOTH --pick and
+    // non-pick paths. This can be either two inline checks or a shared helper.
     const mainFunc = src.slice(src.indexOf('async function main()'));
-    const pickInterception = mainFunc.indexOf('// When --pick is active');
-    const fileResolution = mainFunc.indexOf('@file:');
-
-    // There should be at least two @file: resolution points:
-    // one in the --pick path and one in the normal path
-    const firstAt = mainFunc.indexOf("'@file:'");
-    const secondAt = mainFunc.indexOf("'@file:'", firstAt + 1);
-    assert.ok(secondAt > firstAt,
-      'Both --pick and normal paths should resolve @file: references');
+    const resolveCalls = (mainFunc.match(/resolveAtFileOutput\(/g) || []).length;
+    const inlineAtFileChecks = (mainFunc.match(/@file:/g) || []).length;
+    assert.ok(
+      resolveCalls >= 2 || inlineAtFileChecks >= 2,
+      'Both --pick and normal paths should resolve @file: references'
+    );
   });
 });

tests/bug-224-pick-stdout-capture.test.cjs

@@ -0,0 +1,40 @@
+// allow-test-rule: structural-implementation-guard
+// Bug #224 is a platform-specific (Node 24 + Windows) flake in `--pick` where
+// stdout interception can produce non-deterministic failures. We lock the seam
+// contract structurally until we have a deterministic Windows reproduction
+// harness in CI.
+
+'use strict';
+
+const { describe, test, before } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+const { runGsdTools } = require('./helpers.cjs');
+
+const GSD_TOOLS_SRC = path.join(__dirname, '..', 'get-shit-done', 'bin', 'gsd-tools.cjs');
+
+describe('bug #224: --pick stdout capture contract', () => {
+  let src;
+
+  before(() => {
+    src = fs.readFileSync(GSD_TOOLS_SRC, 'utf-8');
+  });
+
+  test('--pick output still succeeds for current-timestamp command', () => {
+    const result = runGsdTools(['current-timestamp', '--pick', 'timestamp']);
+    assert.strictEqual(result.success, true, result.error || 'expected command to succeed');
+    assert.match(result.output, /^\d{4}-\d{2}-\d{2}T/, 'expected ISO timestamp output');
+  });
+
+  test('stdout interception for fd=1 returns a byte count (never undefined)', () => {
+    const mainStart = src.indexOf('async function main()');
+    assert.ok(mainStart !== -1, 'main() must exist');
+    const mainSrc = src.slice(mainStart);
+
+    assert.ok(
+      mainSrc.includes('Buffer.byteLength(') || mainSrc.includes('return data.length'),
+      'stdout interception must return written-byte counts for fd=1 captures'
+    );
+  });
+});