From 2b0346fe84c968195671a349c30bbfe35a89e38b Mon Sep 17 00:00:00 2001
From: Ben Warzeski <bwarzeski@edx.org>
Date: Wed, 23 Feb 2022 11:55:53 -0500
Subject: [PATCH] chore: add tests for EditorHeader hooks (#18)

---
 src/editors/components/EditorHeader/hooks.js  |  69 +++++---
 .../components/EditorHeader/hooks.test.js     | 154 ++++++++++++++++++
 2 files changed, 199 insertions(+), 24 deletions(-)
 create mode 100644 src/editors/components/EditorHeader/hooks.test.js

diff --git a/src/editors/components/EditorHeader/hooks.js b/src/editors/components/EditorHeader/hooks.js
index 2b2c7fd6c..42a490a32 100644
--- a/src/editors/components/EditorHeader/hooks.js
+++ b/src/editors/components/EditorHeader/hooks.js
@@ -1,23 +1,31 @@
 import React from 'react';
+import * as module from './hooks';
 
-/* eslint-disable import/prefer-default-export */
-export const localTitleHooks = ({
-  editorRef,
-  setBlockTitle,
-  typeHeader,
-}) => {
-  console.log('localTitleHooks');
-  const [isEditing, setIsEditing] = React.useState(false);
-  const startEditing = () => setIsEditing(true);
-  const stopEditing = () => setIsEditing(false);
-  const [localTitle, setLocalTitle] = React.useState(typeHeader);
-  const inputRef = React.createRef();
-  const updateTitle = () => {
-    setBlockTitle(localTitle);
-    stopEditing();
-  };
-
-  const handleKeyDown = (e) => {
+export const hooks = {
+  isEditing: () => {
+    const [isEditing, setIsEditing] = React.useState(false);
+    return {
+      isEditing,
+      startEditing: () => setIsEditing(true),
+      stopEditing: () => setIsEditing(false),
+    };
+  },
+  localTitle: ({
+    setBlockTitle,
+    stopEditing,
+    typeHeader,
+  }) => {
+    const [localTitle, setLocalTitle] = React.useState(typeHeader);
+    return {
+      updateTitle: () => {
+        setBlockTitle(localTitle);
+        stopEditing();
+      },
+      handleChange: (e) => setLocalTitle(e.target.value),
+      localTitle,
+    };
+  },
+  handleKeyDown: ({ stopEditing, editorRef }) => (e) => {
     if (e.key === 'Enter') {
       stopEditing();
     }
@@ -25,18 +33,31 @@ export const localTitleHooks = ({
       e.preventDefault();
       editorRef.current.focus();
     }
-  };
-
-  const handleChange = (e) => setLocalTitle(e.target.value);
+  },
+};
 
+/* eslint-disable import/prefer-default-export */
+export const localTitleHooks = ({
+  editorRef,
+  setBlockTitle,
+  typeHeader,
+}) => {
+  const { isEditing, startEditing, stopEditing } = module.hooks.isEditing();
+  const { localTitle, handleChange, updateTitle } = module.hooks.localTitle({
+    setBlockTitle,
+    stopEditing,
+    typeHeader,
+  });
   return {
     isEditing,
-    handleChange,
     startEditing,
     stopEditing,
+
     localTitle,
-    inputRef,
-    handleKeyDown,
     updateTitle,
+    handleChange,
+
+    inputRef: React.createRef(),
+    handleKeyDown: module.hooks.handleKeyDown({ stopEditing, editorRef }),
   };
 };
diff --git a/src/editors/components/EditorHeader/hooks.test.js b/src/editors/components/EditorHeader/hooks.test.js
new file mode 100644
index 000000000..a6f182150
--- /dev/null
+++ b/src/editors/components/EditorHeader/hooks.test.js
@@ -0,0 +1,154 @@
+import React from 'react';
+import * as module from './hooks';
+
+jest.mock('react', () => {
+  const updateState = jest.fn();
+  return {
+    updateState,
+    useState: jest.fn(val => ([{ state: val }, (newVal) => updateState({ val, newVal })])),
+    createRef: jest.fn(val => ({ ref: val })),
+  };
+});
+
+describe('EditorHeader hooks', () => {
+  const editorRef = { current: {} };
+  const typeHeader = 'Type Header';
+  let setBlockTitle;
+  let output;
+  beforeEach(() => {
+    setBlockTitle = jest.fn();
+  });
+  describe('base hooks', () => {
+    describe('isEditing', () => {
+      beforeEach(() => {
+        output = module.hooks.isEditing();
+      });
+      test('returns isEditing field, defaulted to false', () => {
+        expect(output.isEditing).toEqual({ state: false });
+      });
+      test('startEditing calls the setter function with true', () => {
+        output.startEditing();
+        expect(React.updateState).toHaveBeenCalledWith({ val: false, newVal: true });
+      });
+      test('stopEditign calls the setter function with false', () => {
+        output.stopEditing();
+        expect(React.updateState).toHaveBeenCalledWith({ val: false, newVal: false });
+      });
+    });
+    describe('localTitle', () => {
+      let stopEditing;
+      beforeEach(() => {
+        stopEditing = jest.fn();
+        output = module.hooks.localTitle({
+          setBlockTitle,
+          stopEditing,
+          typeHeader,
+        });
+      });
+      test('returns the state value for localTitle, defaulted to typeHeader', () => {
+        expect(output.localTitle).toEqual({ state: typeHeader });
+      });
+      describe('updateTitle hook', () => {
+        it('calls setBlockTitle with localTitle, and stopEditing', () => {
+          output.updateTitle();
+          expect(setBlockTitle).toHaveBeenCalledWith(output.localTitle);
+          expect(stopEditing).toHaveBeenCalled();
+        });
+      });
+      describe('handleChange', () => {
+        it('calls setLocalTitle with the event target value', () => {
+          const value = 'SOME VALUe';
+          output.handleChange({ target: { value } });
+          expect(React.updateState).toHaveBeenCalledWith({
+            val: typeHeader,
+            newVal: value,
+          });
+        });
+      });
+    });
+    describe('handleKeyDown', () => {
+      let stopEditing;
+      beforeEach(() => {
+        stopEditing = jest.fn();
+        editorRef.current.focus = jest.fn();
+        output = module.hooks.handleKeyDown({ stopEditing, editorRef });
+      });
+      describe('Enter-key event', () => {
+        it('calls stopEditing', () => {
+          output({ key: 'Enter' });
+          expect(stopEditing).toHaveBeenCalled();
+        });
+      });
+      describe('tab event', () => {
+        it('calls preventDefault on the event, and focuses to the editorRef', () => {
+          const preventDefault = jest.fn();
+          output({ key: 'Tab', preventDefault });
+          expect(preventDefault).toHaveBeenCalled();
+          expect(editorRef.current.focus).toHaveBeenCalled();
+        });
+        it('does nothing if editorRef is not instantiated', () => {
+          const preventDefault = jest.fn();
+          output = module.hooks.handleKeyDown({ stopEditing, editorRef: null });
+          output({ key: 'Tab', preventDefault });
+          expect(preventDefault).not.toHaveBeenCalled();
+        });
+      });
+    });
+  });
+  describe('local title hooks', () => {
+    let oldHooks;
+    const values = {
+      isEditing: 'ISeDITING',
+      startEditing: 'STARTeDITING',
+      stopEditing: 'STOPeDITING',
+      handleChange: 'HANDLEcHANGE',
+      localTitle: 'LOCALtITLE',
+    };
+    const newHooks = {
+      isEditing: () => ({
+        isEditing: values.isEditing,
+        startEditing: values.startEditing,
+        stopEditing: values.stopEditing,
+      }),
+      localTitle: jest.fn((args) => ({
+        updateTitle: args,
+        handleChange: values.handleChange,
+        localTitle: values.localTitle,
+      })),
+      handleKeyDown: jest.fn(args => ({ handleKeyDown: args })),
+    };
+    beforeEach(() => {
+      oldHooks = module.hooks;
+      module.hooks.isEditing = newHooks.isEditing;
+      module.hooks.localTitle = newHooks.localTitle;
+      module.hooks.handleKeyDown = newHooks.handleKeyDown;
+      output = module.localTitleHooks({ editorRef, setBlockTitle, typeHeader });
+    });
+    afterEach(() => {
+      module.hooks = oldHooks;
+    });
+    it('returns isEditing, startEditing, and stopEditing, tied to the isEditing hook', () => {
+      expect(output.isEditing).toEqual(values.isEditing);
+      expect(output.startEditing).toEqual(values.startEditing);
+      expect(output.stopEditing).toEqual(values.stopEditing);
+    });
+    it('returns localTitle, updateTitle, and handleChange, tied to the localTitle hook', () => { 
+      expect(output.updateTitle).toEqual({
+        setBlockTitle,
+        stopEditing: values.stopEditing,
+        typeHeader,
+      });
+      expect(output.handleChange).toEqual(values.handleChange);
+      expect(output.localTitle).toEqual(values.localTitle);
+    });
+    it('returns a new ref for inputRef', () => {
+      expect(output.inputRef).toEqual({ ref: undefined });
+    });
+    it('returns handleKeyDown, tied to handleKeyDown hook', () => {
+      expect(output.handleKeyDown).toEqual(newHooks.handleKeyDown({
+        stopEditing: values.stopEditing,
+        editorRef,
+      }));
+    });
+  });
+});