Restructure source and tests

__tests__/main.test.js

@@ -0,0 +1,100 @@
+/**
+ * Unit tests for the action's main functionality, src/main.ts
+ *
+ * These should be run as if the action was called from a workflow.
+ * Specifically, the inputs listed in `action.yml` should be set as environment
+ * variables following the pattern `INPUT_<INPUT_NAME>`.
+ */
+const core = require('@actions/core')
+const main = require('../src/main')
+
+// Mock the GitHub Actions core library
+const debugMock = jest.spyOn(core, 'debug').mockImplementation()
+const getInputMock = jest.spyOn(core, 'getInput').mockImplementation()
+const setFailedMock = jest.spyOn(core, 'setFailed').mockImplementation()
+const setOutputMock = jest.spyOn(core, 'setOutput').mockImplementation()
+
+// Mock the action's main function
+const runMock = jest.spyOn(main, 'run')
+
+// Other utilities
+const timeRegex = /^\d{2}:\d{2}:\d{2}/
+
+describe('action', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('sets the time output', async () => {
+    // Set the action's inputs as return values from core.getInput()
+    getInputMock.mockImplementation(name => {
+      switch (name) {
+        case 'milliseconds':
+          return '500'
+        default:
+          return ''
+      }
+    })
+
+    await main.run()
+    expect(runMock).toHaveReturned()
+
+    // Verify that all of the core library functions were called correctly
+    expect(debugMock).toHaveBeenNthCalledWith(1, 'Waiting 500 milliseconds ...')
+    expect(debugMock).toHaveBeenNthCalledWith(
+      2,
+      expect.stringMatching(timeRegex)
+    )
+    expect(debugMock).toHaveBeenNthCalledWith(
+      3,
+      expect.stringMatching(timeRegex)
+    )
+    expect(setOutputMock).toHaveBeenNthCalledWith(
+      1,
+      'time',
+      expect.stringMatching(timeRegex)
+    )
+  })
+
+  it('sets a failed status', async () => {
+    // Set the action's inputs as return values from core.getInput()
+    getInputMock.mockImplementation(name => {
+      switch (name) {
+        case 'milliseconds':
+          return 'this is not a number'
+        default:
+          return ''
+      }
+    })
+
+    await main.run()
+    expect(runMock).toHaveReturned()
+
+    // Verify that all of the core library functions were called correctly
+    expect(setFailedMock).toHaveBeenNthCalledWith(
+      1,
+      'milliseconds not a number'
+    )
+  })
+
+  it('fails if no input is provided', async () => {
+    // Set the action's inputs as return values from core.getInput()
+    getInputMock.mockImplementation(name => {
+      switch (name) {
+        case 'milliseconds':
+          throw new Error('Input required and not supplied: milliseconds')
+        default:
+          return ''
+      }
+    })
+
+    await main.run()
+    expect(runMock).toHaveReturned()
+
+    // Verify that all of the core library functions were called correctly
+    expect(setFailedMock).toHaveBeenNthCalledWith(
+      1,
+      'Input required and not supplied: milliseconds'
+    )
+  })
+})