feat: Chainable sh mock commands

It's now possible to include several commands in one chain:

```ts
sh.mock()
  .command('a').returns({ stdout: 'output from a' })
  .command('b').returns({ stdout: 'output from b' })
// ...
```

Author: seb-cr

README.md

@@ -115,13 +115,15 @@ When you're done, use `sh.restore()` to stop mocking.
 // activate mock mode
 const mock = sh.mock();
 
-// add some default mocks
-mock.returns({ stdout: 'first call' });
-mock.returns({ stdout: 'second call' });
+// add some default mocks (you can chain these methods)
+mock
+  .returns({ stdout: 'first call' })
+  .returns({ stdout: 'second call' });
 
 // add some command-specific mocks
-mock.command('cat file.txt').returns({ stdout: 'file contents' });
-mock.command(/echo/).returns({ stdout: 'mock echo' });
+mock
+  .command('cat file.txt').returns({ stdout: 'file contents' })
+  .command(/echo/).returns({ stdout: 'mock echo' });
 
 await sh('some arbitrary command');
 // => 'first call'

src/shell.ts

@@ -79,6 +79,13 @@ export interface MockShCommandController {
    * @param [mock.stderr] The mock stderr output.
    */
   returns(mock: { exitCode?: number, stdout?: string, stderr?: string }): MockShCommandController;
+
+  /**
+   * Ends this chain and starts a new command matcher.
+   *
+   * @param command The command to match.
+   */
+  command(command: string | RegExp): MockShCommandController;
 }
 
 export interface MockShController {
@@ -201,7 +208,12 @@ sh.mock = () => {
           mocks.push({ exitCode, stdout, stderr });
           return cmdController;
         },
+
+        command(newCommand: string | RegExp) {
+          return mockController.command(newCommand);
+        },
       };
+
       return cmdController;
     },
 

tests/shell.spec.ts

@@ -44,20 +44,22 @@ describe('sh mock mode', () => {
     it('should work as demonstrated', async () => {
       const mock = sh.mock();
 
-      mock.returns({ stdout: 'First call' });
-      mock.returns({ stdout: 'Second call' });
+      mock
+        .returns({ stdout: 'first call' })
+        .returns({ stdout: 'second call' });
 
-      mock.command('cat file.txt').returns({ stdout: 'file contents' });
-      mock.command(/echo/).returns({ stdout: 'mock echo!' });
+      mock
+        .command('cat file.txt').returns({ stdout: 'file contents' })
+        .command(/echo/).returns({ stdout: 'mock echo' });
 
       let result = await sh('some arbitrary command');
-      expect(result).to.equal('First call');
+      expect(result).to.equal('first call');
 
       result = await sh('some arbitrary command');
-      expect(result).to.equal('Second call');
+      expect(result).to.equal('second call');
 
       result = await sh('echo "hi there"');
-      expect(result).to.equal('mock echo!');
+      expect(result).to.equal('mock echo');
 
       result = await sh('cat file.txt');
       expect(result).to.equal('file contents');
@@ -98,11 +100,11 @@ describe('sh mock mode', () => {
 
   describe('matching mocks', () => {
     it('should return the mock results for the matching command', async () => {
-      const mock = sh.mock();
-      mock.command('a')
+      sh.mock()
+        .command('a')
         .returns({ stdout: 'first a' })
-        .returns({ stdout: 'second a' });
-      mock.command('b')
+        .returns({ stdout: 'second a' })
+        .command('b')
         .returns({ stdout: 'first b' })
         .returns({ stdout: 'second b' });