Refactored recursive part of file_row to file_tree

**Note:**
- Also, introduces some components which will be used for
  IDE and diff row specific things.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23720

app/assets/javascripts/diffs/components/diff_file_row.vue

+<script>
+/**
+ * This component is an iterative step towards refactoring and simplifying `vue_shared/components/file_row.vue`
+ * https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23720
+ */
+import FileRow from '~/vue_shared/components/file_row.vue';
+
+export default {
+  components: {
+    FileRow,
+  },
+};
+</script>
+
+<template>
+  <file-row v-bind="$attrs" v-on="$listeners" />
+</template>

app/assets/javascripts/diffs/components/tree_list.vue

@@ -3,7 +3,8 @@ import { mapActions, mapGetters, mapState } from 'vuex';
 import { GlTooltipDirective } from '@gitlab/ui';
 import { s__, sprintf } from '~/locale';
 import Icon from '~/vue_shared/components/icon.vue';
-import FileRow from '~/vue_shared/components/file_row.vue';
+import FileTree from '~/vue_shared/components/file_tree.vue';
+import DiffFileRow from './diff_file_row.vue';
 import FileRowStats from './file_row_stats.vue';
 
 export default {
@@ -12,7 +13,7 @@ export default {
   },
   components: {
     Icon,
-    FileRow,
+    FileTree,
   },
   props: {
     hideFileStats: {
@@ -61,6 +62,7 @@ export default {
   searchPlaceholder: sprintf(s__('MergeRequest|Search files (%{modifier_key}P)'), {
     modifier_key: /Mac/i.test(navigator.userAgent) ? '⌘' : 'Ctrl+',
   }),
+  DiffFileRow,
 };
 </script>
 
@@ -91,7 +93,7 @@ export default {
     </div>
     <div :class="{ 'pt-0 tree-list-blobs': !renderTreeList }" class="tree-list-scroll">
       <template v-if="filteredTreeList.length">
-        <file-row
+        <file-tree
           v-for="file in filteredTreeList"
           :key="file.key"
           :file="file"
@@ -99,6 +101,7 @@ export default {
           :hide-extra-on-tree="true"
           :extra-component="fileRowExtraComponent"
           :show-changed-icon="true"
+          :file-row-component="$options.DiffFileRow"
           @toggleTreeOpen="toggleTreeOpen"
           @clickFile="scrollToFile"
         />

app/assets/javascripts/ide/components/ide_file_row.vue

+<script>
+/**
+ * This component is an iterative step towards refactoring and simplifying `vue_shared/components/file_row.vue`
+ * https://gitlab.com/gitlab-org/gitlab/-/merge_requests/23720
+ */
+import FileRow from '~/vue_shared/components/file_row.vue';
+
+export default {
+  components: {
+    FileRow,
+  },
+};
+</script>
+
+<template>
+  <file-row v-bind="$attrs" v-on="$listeners" />
+</template>

app/assets/javascripts/ide/components/ide_tree_list.vue

 <script>
 import { mapActions, mapGetters, mapState } from 'vuex';
 import { GlSkeletonLoading } from '@gitlab/ui';
-import FileRow from '~/vue_shared/components/file_row.vue';
+import FileTree from '~/vue_shared/components/file_tree.vue';
+import IdeFileRow from './ide_file_row.vue';
 import NavDropdown from './nav_dropdown.vue';
 import FileRowExtra from './file_row_extra.vue';
 
@@ -9,7 +10,7 @@ export default {
   components: {
     GlSkeletonLoading,
     NavDropdown,
-    FileRow,
+    FileTree,
   },
   props: {
     viewerType: {
@@ -36,6 +37,7 @@ export default {
     ...mapActions(['updateViewer', 'toggleTreeOpen']),
   },
   FileRowExtra,
+  IdeFileRow,
 };
 </script>
 
@@ -53,12 +55,13 @@ export default {
       </header>
       <div class="ide-tree-body h-100">
         <template v-if="currentTree.tree.length">
-          <file-row
+          <file-tree
             v-for="file in currentTree.tree"
             :key="file.key"
             :file="file"
             :level="0"
             :extra-component="$options.FileRowExtra"
+            :file-row-component="$options.IdeFileRow"
             @toggleTreeOpen="toggleTreeOpen"
           />
         </template>

app/assets/javascripts/vue_shared/components/file_row.vue

@@ -62,9 +62,6 @@ export default {
         'is-open': this.file.opened,
       };
     },
-    childFilesLevel() {
-      return this.file.isHeader ? 0 : this.level + 1;
-    },
   },
   watch: {
     'file.active': function fileActiveWatch(active) {
@@ -131,7 +128,6 @@ export default {
 </script>
 
 <template>
-  <div>
   <file-header v-if="file.isHeader" :path="file.path" />
   <div
     v-else
@@ -165,20 +161,6 @@ export default {
       />
     </div>
   </div>
-    <template v-if="file.opened || file.isHeader">
-      <file-row
-        v-for="childFile in file.tree"
-        :key="childFile.key"
-        :file="childFile"
-        :level="childFilesLevel"
-        :hide-extra-on-tree="hideExtraOnTree"
-        :extra-component="extraComponent"
-        :show-changed-icon="showChangedIcon"
-        @toggleTreeOpen="toggleTreeOpen"
-        @clickFile="clickedFile"
-      />
-    </template>
-  </div>
 </template>
 
 <style>

app/assets/javascripts/vue_shared/components/file_tree.vue

+<script>
+export default {
+  name: 'FileTree',
+  props: {
+    fileRowComponent: {
+      type: Object,
+      required: true,
+    },
+    level: {
+      type: Number,
+      required: true,
+    },
+    file: {
+      type: Object,
+      required: true,
+    },
+  },
+  computed: {
+    childFilesLevel() {
+      return this.file.isHeader ? 0 : this.level + 1;
+    },
+  },
+};
+</script>
+
+<template>
+  <div>
+    <component
+      :is="fileRowComponent"
+      :level="level"
+      :file="file"
+      v-bind="$attrs"
+      v-on="$listeners"
+    />
+    <template v-if="file.opened || file.isHeader">
+      <file-tree
+        v-for="childFile in file.tree"
+        :key="childFile.key"
+        :file-row-component="fileRowComponent"
+        :level="childFilesLevel"
+        :file="childFile"
+        v-bind="$attrs"
+        v-on="$listeners"
+      />
+    </template>
+  </div>
+</template>

spec/frontend/diffs/components/diff_file_row_spec.js

+import { shallowMount } from '@vue/test-utils';
+import DiffFileRow from '~/diffs/components/diff_file_row.vue';
+import FileRow from '~/vue_shared/components/file_row.vue';
+
+describe('Diff File Row component', () => {
+  let wrapper;
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(DiffFileRow, {
+      propsData: { ...props },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  it('renders file row component', () => {
+    createComponent({
+      level: 4,
+      file: {},
+    });
+    expect(wrapper.find(FileRow).exists()).toEqual(true);
+  });
+});

spec/frontend/ide/components/ide_file_row_spec.js

+import { shallowMount } from '@vue/test-utils';
+import IdeFileRow from '~/ide/components/ide_file_row.vue';
+import FileRow from '~/vue_shared/components/file_row.vue';
+
+describe('Ide File Row component', () => {
+  let wrapper;
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(IdeFileRow, {
+      propsData: { ...props },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  it('renders file row component', () => {
+    createComponent({
+      level: 4,
+      file: {},
+    });
+    expect(wrapper.find(FileRow).exists()).toEqual(true);
+  });
+});

spec/frontend/vue_shared/components/file_tree_spec.js

+import { pick } from 'lodash';
+import { shallowMount } from '@vue/test-utils';
+import FileTree from '~/vue_shared/components/file_tree.vue';
+
+const MockFileRow = {
+  name: 'MockFileRow',
+  render() {
+    return this.$slots.default;
+  },
+};
+
+const TEST_LEVEL = 4;
+const TEST_EXTA_ARGS = {
+  foo: 'lorem-ipsum',
+  bar: 'zoo',
+};
+
+describe('File Tree component', () => {
+  let wrapper;
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(FileTree, {
+      propsData: { level: TEST_LEVEL, fileRowComponent: MockFileRow, ...props },
+      attrs: { ...TEST_EXTA_ARGS },
+    });
+  };
+
+  const findFileRow = () => wrapper.find(MockFileRow);
+  const findChildrenTrees = () => wrapper.findAll(FileTree).wrappers.slice(1);
+  const findChildrenTreeProps = () =>
+    findChildrenTrees().map(x => ({
+      ...x.props(),
+      ...pick(x.attributes(), Object.keys(TEST_EXTA_ARGS)),
+    }));
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  describe('file row component', () => {
+    beforeEach(() => {
+      createComponent({ file: {} });
+    });
+
+    it('renders file row component', () => {
+      expect(findFileRow().exists()).toEqual(true);
+    });
+
+    it('contains the required attribute keys', () => {
+      const fileRow = findFileRow();
+
+      // Checking strings b/c value in attributes are always strings
+      expect(fileRow.attributes()).toEqual({
+        file: {}.toString(),
+        level: TEST_LEVEL.toString(),
+        ...TEST_EXTA_ARGS,
+      });
+    });
+  });
+
+  describe('file tree', () => {
+    const createChildren = () => [{ id: 1 }, { id: 2 }];
+    const createChildrenExpectation = (props = {}) =>
+      createChildren().map(file => ({
+        fileRowComponent: MockFileRow,
+        file,
+        ...TEST_EXTA_ARGS,
+        ...props,
+      }));
+
+    it.each`
+      key           | value    | desc                             | expectedChildren
+      ${'isHeader'} | ${true}  | ${'is shown if file is header'}  | ${createChildrenExpectation({ level: 0 })}
+      ${'opened'}   | ${true}  | ${'is shown if file is open'}    | ${createChildrenExpectation({ level: TEST_LEVEL + 1 })}
+      ${'isHeader'} | ${false} | ${'is hidden if file is header'} | ${[]}
+      ${'opened'}   | ${false} | ${'is hidden if file is open'}   | ${[]}
+    `('$desc', ({ key, value, expectedChildren }) => {
+      createComponent({
+        file: {
+          [key]: value,
+          tree: createChildren(),
+        },
+      });
+
+      expect(findChildrenTreeProps()).toEqual(expectedChildren);
+    });
+  });
+});

spec/javascripts/vue_shared/components/file_row_spec.js

@@ -19,7 +19,6 @@ describe('File row component', () => {
 
   const findNewDropdown = () => vm.$el.querySelector('.ide-new-btn .dropdown');
   const findNewDropdownButton = () => vm.$el.querySelector('.ide-new-btn .dropdown button');
-  const findFileRow = () => vm.$el.querySelector('.file-row');
 
   it('renders name', () => {
     createComponent({
@@ -42,7 +41,7 @@ describe('File row component', () => {
     });
     spyOn(vm, '$emit').and.stub();
 
-    vm.$el.querySelector('.file-row').click();
+    vm.$el.click();
 
     expect(vm.$emit).toHaveBeenCalledWith('toggleTreeOpen', vm.file.path);
   });
@@ -87,7 +86,7 @@ describe('File row component', () => {
       level: 0,
     });
 
-    expect(vm.$el.querySelector('.js-file-row-header')).not.toBe(null);
+    expect(vm.$el.classList).toContain('js-file-row-header');
   });
 
   describe('new dropdown', () => {
@@ -138,7 +137,7 @@ describe('File row component', () => {
       });
 
       it('closes when row triggers mouseleave', () => {
-        findFileRow().dispatchEvent(new Event('mouseleave'));
+        vm.$el.dispatchEvent(new Event('mouseleave'));
 
         expect(vm.dropdownOpen).toBe(false);
       });