fix: preserve skill install order when batching

Author: chenjiahan

src/index.ts

@@ -461,6 +461,22 @@ async function runSkillCommand(
   installationTaskLog.success(`Installed ${skillNoun} ${skillLabel}`);
 }
 
+function groupContiguousSkillsBySource(skills: ExtraSkill[]) {
+  const skillGroups: ExtraSkill[][] = [];
+
+  for (const skill of skills) {
+    const lastGroup = skillGroups.at(-1);
+    if (lastGroup?.[0]?.source === skill.source) {
+      lastGroup.push(skill);
+      continue;
+    }
+
+    skillGroups.push([skill]);
+  }
+
+  return skillGroups;
+}
+
 export async function create({
   name,
   root,
@@ -603,15 +619,8 @@ export async function create({
     )
     .filter((skill): skill is ExtraSkill => Boolean(skill));
 
-  // Group selected skills by source so each repository is installed once.
-  const skillGroups = new Map<string, ExtraSkill[]>();
-  for (const skill of selectedExtraSkills) {
-    const currentSkills = skillGroups.get(skill.source) ?? [];
-    currentSkills.push(skill);
-    skillGroups.set(skill.source, currentSkills);
-  }
-
-  for (const groupedSkills of skillGroups.values()) {
+  // Batch only contiguous skills from the same source to preserve install order.
+  for (const groupedSkills of groupContiguousSkillsBySource(selectedExtraSkills)) {
     await runSkillCommand(groupedSkills, distFolder);
   }
 

test/skills.test.ts

@@ -483,6 +483,110 @@ test('should install selected extra skills from repeated --skill flags', async (
   });
 });
 
+test('should preserve skill install order when the same source appears non-contiguously', async () => {
+  const projectDir = path.join(testDir, 'skills-preserve-order');
+  const calls = createExecCommand();
+
+  await create({
+    name: 'test',
+    root: fixturesDir,
+    templates: ['vanilla'],
+    getTemplateName: async () => 'vanilla',
+    extraSkills: [
+      {
+        value: 'rstest-best-practices',
+        label: 'Rstest Best Practices',
+        source: 'rstackjs/agent-skills',
+      },
+      {
+        value: 'docs-writer',
+        label: 'Docs Writer',
+        source: 'acme/skills',
+      },
+      {
+        value: 'rsbuild-best-practices',
+        label: 'Rsbuild Best Practices',
+        source: 'rstackjs/agent-skills',
+      },
+    ],
+    argv: [
+      'node',
+      'test',
+      '--dir',
+      projectDir,
+      '--template',
+      'vanilla',
+      '--skill',
+      'rstest-best-practices,docs-writer,rsbuild-best-practices',
+    ],
+  });
+
+  expect(calls).toHaveLength(3);
+  expect(calls[0]).toEqual({
+    args: [
+      '-y',
+      'skills',
+      'add',
+      'rstackjs/agent-skills',
+      '--agent',
+      'universal',
+      '--yes',
+      '--copy',
+      '--skill',
+      'rstest-best-practices',
+    ],
+    command: 'npx',
+    options: expect.objectContaining({
+      nodeOptions: expect.objectContaining({
+        cwd: projectDir,
+        stdio: 'pipe',
+      }),
+    }),
+  });
+  expect(calls[1]).toEqual({
+    args: [
+      '-y',
+      'skills',
+      'add',
+      'acme/skills',
+      '--agent',
+      'universal',
+      '--yes',
+      '--copy',
+      '--skill',
+      'docs-writer',
+    ],
+    command: 'npx',
+    options: expect.objectContaining({
+      nodeOptions: expect.objectContaining({
+        cwd: projectDir,
+        stdio: 'pipe',
+      }),
+    }),
+  });
+  expect(calls[2]).toEqual({
+    args: [
+      '-y',
+      'skills',
+      'add',
+      'rstackjs/agent-skills',
+      '--agent',
+      'universal',
+      '--yes',
+      '--copy',
+      '--skill',
+      'rsbuild-best-practices',
+    ],
+    command: 'npx',
+    options: expect.objectContaining({
+      nodeOptions: expect.objectContaining({
+        cwd: projectDir,
+        stdio: 'pipe',
+      }),
+    }),
+  });
+});
+
 test('should skip the skills prompt when --skill is provided', async () => {
   const projectDir = path.join(testDir, 'skills-skip-prompt-with-cli-option');
   const calls = createExecCommand();