diff --git a/__tests__/changedFiles.test.ts b/__tests__/changedFiles.test.ts
new file mode 100644
index 00000000..d0ecd57b
--- /dev/null
+++ b/__tests__/changedFiles.test.ts
@@ -0,0 +1,69 @@
+import * as github from '@actions/github';
+import {
+  checkAll,
+  checkAny,
+  toChangedFilesMatchConfig
+} from '../src/changedFiles';
+
+jest.mock('@actions/core');
+jest.mock('@actions/github');
+
+describe(checkAll, () => {
+  describe('when all the patterns match', () => {
+    it.todo('returns true');
+  });
+
+  describe('when no the patterns match', () => {
+    it.todo('returns false');
+  });
+});
+
+describe(checkAny, () => {
+  describe('when any provided patterns matches one of the files changed', () => {
+    it.todo('returns true');
+  });
+
+  describe('when no the patterns match', () => {
+    it.todo('returns false');
+  });
+});
+
+describe(toChangedFilesMatchConfig, () => {
+  describe(`when there is no 'changed-files' key in the config`, () => {
+    it.todo('returns an empty object');
+  });
+
+  describe(`when there is a 'changed-files' key in the config`, () => {
+    describe(`and it contains a 'all' key`, () => {
+      describe('with a value of a string', () => {
+        it.todo(
+          'sets the value to be an array of strings in the config object'
+        );
+      });
+
+      describe('with a value of an array of strings', () => {
+        it.todo('sets the value in the config object');
+      });
+    });
+
+    describe(`and it contains a 'any' key`, () => {
+      describe('with a value of a string', () => {
+        it.todo(
+          'sets the value to be an array of strings on the config object'
+        );
+      });
+
+      describe('with a value of an array of strings', () => {
+        it.todo('sets the value in the config object');
+      });
+    });
+
+    describe('and the value is a string', () => {
+      it.todo(`sets the string as an array under an 'any' key`);
+    });
+
+    describe('and the value is an array of strings', () => {
+      it.todo(`sets the array under an 'any' key`);
+    });
+  });
+});