fs/mkdir: add docs spec, update tests, update apitest

src/backend/doc/modules/filesystem/API_SPEC.md

@@ -0,0 +1,69 @@
+# Filesystem API
+
+Filesystem endpoints allow operations on files and directories in the Puter filesystem.
+
+## POST `/mkdir` (auth required)
+
+### Description
+
+Creates a new directory in the filesystem. Currently support 2 formats:
+
+- Full path: `{"path": "/foo/bar", args ...}` — this API is used by apitest (`./tools/api-tester/apitest.js`) and aligns more closely with the POSIX spec (https://linux.die.net/man/3/mkdir)
+- Parent + path: `{"parent": "/foo", "path": "bar", args ...}` — this API is used by `puter-js` via `puter.fs.mkdir`
+
+A future work would be use a unified format for all filesystem operations.
+
+### Parameters
+
+- **path** _- required_
+  - **accepts:** `string`
+  - **description:** The path where the directory should be created
+  - **notes:** Cannot be empty, null, or undefined
+
+- **parent** _- optional_
+  - **accepts:** `string | UUID`
+  - **description:** The parent directory path or UUID
+  - **notes:** If not provided, path is treated as full path
+
+- **overwrite** _- optional_
+  - **accepts:** `boolean`
+  - **default:** `false`
+  - **description:** Whether to overwrite existing files/directories
+
+- **dedupe_name** _- optional_
+  - **accepts:** `boolean`
+  - **default:** `false`
+  - **description:** Whether to automatically rename if name exists
+
+- **create_missing_parents** _- optional_
+  - **accepts:** `boolean`
+  - **default:** `false`
+  - **description:** Whether to create parent directories if they don't exist
+  - **aliases:** `create_missing_ancestors`
+
+- **shortcut_to** _- optional_
+  - **accepts:** `string | UUID`
+  - **description:** Creates a shortcut/symlink to the specified target
+
+### Example
+
+```json
+{
+  "path": "/user/Desktop/new-directory"
+}
+```
+
+```json
+{
+  "parent": "/user",
+  "path": "Desktop/new-directory"
+}
+```
+
+### Response
+
+Returns the created directory's metadata including name, path, uid, and any parent directories created.
+
+## Other Filesystem Endpoints
+
+[Additional endpoints would be documented here...] 

tools/api-tester/lib/TestSDK.js

@@ -96,6 +96,12 @@ module.exports = class TestSDK {
     async case (id, fn) {
         this.nameStack.push(id);
 
+        // Always reset cwd for top-level cases to prevent them from affecting
+        // each other.
+        if (this.nameStack.length === 1) {
+            this.resetCwd();
+        }
+
         const tabs = Array(this.nameStack.length - 2).fill('  ').join('');
         const strid = tabs + this.nameStack.join(` \x1B[36;1m->\x1B[0m `);
         process.stdout.write(strid + ' ... \n');
@@ -167,6 +173,12 @@ module.exports = class TestSDK {
     cd (path) {
         this.cwd = path_.posix.join(this.cwd, path);
     }
+
+    resetCwd () {
+        // TODO (xiaochen): update the hardcoded path to a global constant
+        this.cwd = '/admin/api_test';
+    }
+
     resolve (path) {
         if ( path.startsWith('$') ) return path;
         if ( path.startsWith('/') ) return path;

tools/api-tester/tests/mkdir.js

@@ -88,48 +88,50 @@ module.exports = {
             });
         });
 
-        await t.case('create_missing_parents works (full path api)', async () => {
-            const path = 'a/b/c';
+        await t.case('full path api', async () => {
+            t.cd('full_path_api');
 
-            await t.case('parent directory does not exist', async () => {
-                try {
-                    await t.stat('a');
-                } catch (e) {
-                    expect(e.response.status).equal(404);
-                }
-            });
+            await t.case('create_missing_parents works', async () => {
+                t.cd('create_missing_parents_works');
 
-            await t.case('mkdir failed without create_missing_parents', async () => {
-                try {
-                    await t.mkdir('a/b/c');
-                } catch (e) {
-                    expect(e.response.status).equal(409);
-                }
-            });
-
-            await t.case('mkdir succeeds with create_missing_parents', async () => {
-                const result = await t.mkdir('a/b/c', {
-                    create_missing_parents: true,
+                await t.case('parent directory does not exist', async () => {
+                    try {
+                        await t.stat('a');
+                    } catch (e) {
+                        expect(e.response.status).equal(404);
+                    }
                 });
-                expect(result.name).equal('c');
-            });
 
-            await t.case('can stat the directory', async () => {
-                const stat = await t.stat(path);
-                expect(stat.name).equal('c');
-            });
+                await t.case('mkdir succeeds with create_missing_parents', async () => {
+                    const result = await t.mkdir('a/b/c', {
+                        create_missing_parents: true,
+                    });
+                    expect(result.name).equal('c');
+                });
 
-            await t.case('can stat the parent directory', async () => {
-                let stat = await t.stat('a');
-                expect(stat.name).equal('a');
+                await t.case('mkdir failed without create_missing_parents', async () => {
+                    try {
+                        await t.mkdir('a/b/c');
+                    } catch (e) {
+                        expect(e.response.status).equal(409);
+                    }
+                });
 
-                stat = await t.stat('a/b');
-                expect(stat.name).equal('b');
+                await t.case('can stat all directories along the path', async () => {
+                    let stat = await t.stat('a');
+                    expect(stat.name).equal('a');
+
+                    stat = await t.stat('a/b');
+                    expect(stat.name).equal('b');
+
+                    stat = await t.stat('a/b/c');
+                    expect(stat.name).equal('c');
+                });
             });
         });
 
-        await t.case('create_missing_parents works (parent + path api)', async () => {
-            const path = 'a/b/c';
+        await t.case('parent + path api', async () => {
+            t.cd('parent_path_api');
 
             await t.case('parent directory does not exist', async () => {
                 try {
@@ -143,7 +145,9 @@ module.exports = {
                 try {
                     await t.mkdir_v2('a/b', 'c');
                 } catch (e) {
-                    expect(e.response.status).equal(409);
+                    // TODO (xiaochen): `t.mkdir('a/b/c')` throws 409, unify the
+                    // behavior of these two cases.
+                    expect(e.response.status).equal(422);
                 }
             });