Add tests for config loading

__tests__/initializer.test.ts

@@ -0,0 +1,43 @@
+import * as core from '@actions/core'
+import * as initializer from '../src/initializer'
+
+describe('initializer', () => {
+  const infoMock = jest.spyOn(core, 'info').mockImplementation(() => {})
+
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('uses the default configuration when no config file is provided', () => {
+    jest.spyOn(core, 'getInput').mockImplementation((name: string): string => {
+      switch (name) {
+        case 'configuration-file-path':
+          return ''
+        default:
+          return 'foo'
+      }
+    })
+
+    const config = initializer.loadConfiguration()
+
+    expect(config).toBeDefined()
+    expect(infoMock).toHaveBeenCalledWith('Using default sizeup configuration')
+  })
+
+  it('can load a custom configuration file', () => {
+    jest.spyOn(core, 'getInput').mockImplementation((name: string): string => {
+      switch (name) {
+        case 'configuration-file-path':
+          return '__tests__/test-configuration.yaml'
+        default:
+          return ''
+      }
+    })
+    const config = initializer.loadConfiguration()
+
+    expect(config).toBeDefined()
+    expect(infoMock).toHaveBeenCalledWith(
+      'Reading sizeup configuration from "__tests__/test-configuration.yaml"'
+    )
+  })
+})

src/initializer.ts

@@ -15,7 +15,7 @@ export function loadConfiguration(): Configuration {
   let configFile = core.getInput('configuration-file-path')
 
   if (configFile) {
-    core.info(`Reading sizeup configuration from ${configFile}`)
+    core.info(`Reading sizeup configuration from "${configFile}"`)
   } else {
     core.info('Using default sizeup configuration')
     configFile = path.resolve(__dirname, './config/default.yaml')