diff --git a/__tests__/main.test.ts b/__tests__/main.test.ts
index b10736d..f27a278 100644
--- a/__tests__/main.test.ts
+++ b/__tests__/main.test.ts
@@ -1,19 +1,18 @@
 import {execSync} from 'child_process';
 import * as path from 'path';
 import * as process from 'process';
-import {getShouldFinalize} from '../src/validate';
+import {getShouldFinalize, getSourcemaps, getStartedAt} from '../src/validate'
 
 describe('validate', () => {
   describe('getShouldFinalize', () => {
+    const errorMessage = 'finalize is not a boolean';
     afterEach(() => {
       delete process.env['INPUT_FINALIZE'];
     });
 
     test('should throw an error when finalize is invalid', async () => {
       process.env['INPUT_FINALIZE'] = 'error';
-      expect(() => getShouldFinalize()).toThrow(
-        'finalize is not a boolean'
-      );
+      expect(() => getShouldFinalize()).toThrow(errorMessage);
     });
 
     test('should return true when finalize is omitted', async () => {
@@ -25,6 +24,57 @@ describe('validate', () => {
       expect(getShouldFinalize()).toBe(false);
     });
   });
+
+  describe('getSourcemaps', () => {
+    afterEach(() => {
+      delete process.env['INPUT_SOURCEMAPS'];
+    });
+
+    test('should return empty list when sourcemaps is omitted', async () => {
+      expect(getSourcemaps()).toEqual([]);
+    });
+
+    test('should return array when sourcemaps is false', () => {
+      process.env['INPUT_SOURCEMAPS'] = './lib';
+      expect(getSourcemaps()).toEqual(['./lib']);
+    });
+  });
+
+  describe('getStartedAt', () => {
+    const errorMessage = 'started_at not in valid format. Unix timestamp or ISO 8601 date expected';
+    afterEach(() => {
+      delete process.env['INPUT_STARTED_AT'];
+    });
+
+    test('should throw an error when started_at is negative', async () => {
+      process.env['INPUT_STARTED_AT'] = '-1';
+      expect(() => getStartedAt()).toThrow(errorMessage);
+    });
+
+    test('should throw an error when started_at is invalid', async () => {
+      process.env['INPUT_STARTED_AT'] = 'error';
+      expect(() => getStartedAt()).toThrow(errorMessage);
+    });
+
+    test('should return null when started_at is omitted', async () => {
+      expect(getStartedAt()).toBeNull();
+    });
+
+    test('should return an integer when started_at is an ISO8601 string.', async () => {
+      process.env['INPUT_STARTED_AT'] = '2017-07-13T19:40:00';
+      expect(getStartedAt()).toEqual(1500000000);
+    });
+
+    test('should return an integer when started_at is an truncated ISO8601 string.', async () => {
+      process.env['INPUT_STARTED_AT'] = '2017-07-13';
+      expect(getStartedAt()).toEqual(1499904000);
+    });
+
+    test('should return an integer when started_at is an integer.', async () => {
+      process.env['INPUT_STARTED_AT'] = '1500000000';
+      expect(getStartedAt()).toEqual(1500000000);
+    });
+  });
 });
 
 // shows how the runner will run a javascript action with env / stdout protocol