From f8c329c8e57c85cc4a394a74802af1f37dcedefd Mon Sep 17 00:00:00 2001
From: Florian Loch <florian.loch@gmail.com>
Date: Wed, 13 May 2020 23:57:22 +0200
Subject: [PATCH] feat: support nested objects in 'fromJSON()'

---
 src/__tests__/volume.test.ts | 29 +++++++++++++++++++++++++++++
 src/volume.ts                | 25 ++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/volume.test.ts b/src/__tests__/volume.test.ts
index 4572fe8b..bea1f6a9 100644
--- a/src/__tests__/volume.test.ts
+++ b/src/__tests__/volume.test.ts
@@ -222,6 +222,35 @@ describe('volume', () => {
         expect(vol.toJSON()).toEqual(json);
       });
 
+      it('Accept a nested dict as input because its nicer to read', () => {
+        const vol1 = new Volume();
+        const vol2 = new Volume();
+
+        const jsonFlat = {
+          '/dir/file': '...',
+          '/dir/dir/dir2/hello.sh': 'world',
+          '/hello.js': 'console.log(123)',
+          '/dir/dir/test.txt': 'Windows',
+        };
+        const jsonNested = {
+          '/dir/': {
+            file: '...',
+            dir: {
+              dir2: {
+                'hello.sh': 'world',
+              },
+              'test.txt': 'Windows',
+            },
+          },
+          '/hello.js': 'console.log(123)',
+        };
+
+        vol1.fromJSON(jsonFlat);
+        vol2.fromJSON(jsonNested);
+
+        expect(vol1.toJSON()).toEqual(vol2.toJSON());
+      });
+
       it('Invalid JSON throws error', () => {
         try {
           const vol = new Volume();
diff --git a/src/volume.ts b/src/volume.ts
index 8849d71c..f0773e7b 100644
--- a/src/volume.ts
+++ b/src/volume.ts
@@ -509,6 +509,10 @@ function validateGid(gid: number) {
 // ---------------------------------------- Volume
 
 export type DirectoryJSON = Record<string, string | null>;
+// tslint:disable-next-line:interface-over-type-literal
+export type NestedDirectoryJSON = {
+  [key: string]: string | NestedDirectoryJSON | null;
+};
 
 /**
  * `Volume` represents a file system.
@@ -864,7 +868,7 @@ export class Volume {
   }
 
   // fromJSON(json: {[filename: string]: string}, cwd: string = '/') {
-  fromJSON(json: DirectoryJSON, cwd: string = process.cwd()) {
+  fromJSON(json: NestedDirectoryJSON, cwd: string = process.cwd()) {
     for (let filename in json) {
       const data = json[filename];
 
@@ -878,6 +882,25 @@ export class Volume {
         this.writeFileSync(filename, data);
       } else {
         this.mkdirpBase(filename, MODE.DIR);
+
+        if (data !== null && typeof data === 'object') {
+          const child: NestedDirectoryJSON = {};
+
+          for (const childFilename in data) {
+            let combinedFilename;
+
+            // the path interpreted as directory could end with the separator symbol...
+            if (filename.endsWith(sep)) {
+              combinedFilename = filename + childFilename;
+            } else {
+              combinedFilename = filename + sep + childFilename;
+            }
+
+            child[combinedFilename] = data[childFilename];
+          }
+
+          this.fromJSON(child, '');
+        }
       }
     }
   }