Add readonly editor to visualize ci config

As a first iteration on the CI editor, this change adds an simple editor
(editor lite) and loads data of a single .gitlab-ci file.

This change uses an graphql queyr that wraps a REST API to load the
contents of the file. Some client side schema definitions were added
for this.

app/assets/javascripts/pipeline_editor/components/text_editor.vue

+<script>
+import EditorLite from '~/vue_shared/components/editor_lite.vue';
+
+export default {
+  components: {
+    EditorLite,
+  },
+  props: {
+    value: {
+      type: String,
+      required: false,
+      default: '',
+    },
+  },
+};
+</script>
+<template>
+  <div class="gl-border-solid gl-border-gray-100 gl-border-1">
+    <editor-lite v-model="value" file-name="*.yml" :editor-options="{ readOnly: true }" />
+  </div>
+</template>

app/assets/javascripts/pipeline_editor/graphql/queries/blob_content.graphql

+query getBlobContent($projectPath: ID!, $path: String, $ref: String!) {
+  blobContent(projectPath: $projectPath, path: $path, ref: $ref) @client {
+    rawData
+  }
+}

app/assets/javascripts/pipeline_editor/graphql/resolvers.js

+import Api from '~/api';
+
+export const resolvers = {
+  Query: {
+    blobContent(_, { projectPath, path, ref }) {
+      return {
+        __typename: 'BlobContent',
+        rawData: Api.getRawFile(projectPath, path, { ref }).then(({ data }) => {
+          return data;
+        }),
+      };
+    },
+  },
+};
+
+export default resolvers;

app/assets/javascripts/pipeline_editor/graphql/typedefs.graphql

+type BlobContent {
+  rawData: String!
+}
+
+extend type Query {
+  blobContent: BlobContent
+}

app/assets/javascripts/pipeline_editor/index.js

 import Vue from 'vue';
+
+import VueApollo from 'vue-apollo';
+import createDefaultClient from '~/lib/graphql';
+import typeDefs from './graphql/typedefs.graphql';
+import { resolvers } from './graphql/resolvers';
+
 import PipelineEditorApp from './pipeline_editor_app.vue';
 
 export const initPipelineEditor = (selector = '#js-pipeline-editor') => {
   const el = document.querySelector(selector);
 
+  const { projectPath, defaultBranch, ciConfigPath } = el?.dataset;
+
+  Vue.use(VueApollo);
+
+  const apolloProvider = new VueApollo({
+    defaultClient: createDefaultClient(resolvers, { typeDefs }),
+  });
+
   return new Vue({
     el,
+    apolloProvider,
     render(h) {
-      return h(PipelineEditorApp);
+      return h(PipelineEditorApp, {
+        props: {
+          projectPath,
+          defaultBranch,
+          ciConfigPath,
+        },
+      });
     },
   });
 };

app/assets/javascripts/pipeline_editor/pipeline_editor_app.vue

 <script>
-import { GlEmptyState } from '@gitlab/ui';
-import { __, s__ } from '~/locale';
+import { GlLoadingIcon, GlAlert } from '@gitlab/ui';
+import { __, s__, sprintf } from '~/locale';
+
+import TextEditor from './components/text_editor.vue';
+
+import getBlobContent from './graphql/queries/blob_content.graphql';
 
 export default {
   components: {
-    GlEmptyState,
+    GlLoadingIcon,
+    GlAlert,
+    TextEditor,
+  },
+  props: {
+    projectPath: {
+      type: String,
+      required: true,
+    },
+    defaultBranch: {
+      type: String,
+      required: false,
+      default: null,
+    },
+    ciConfigPath: {
+      type: String,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      error: null,
+      content: '',
+    };
+  },
+  apollo: {
+    content: {
+      query: getBlobContent,
+      variables() {
+        return {
+          projectPath: this.projectPath,
+          path: this.ciConfigPath,
+          ref: this.defaultBranch,
+        };
+      },
+      update(data) {
+        return data?.blobContent?.rawData;
+      },
+      error(error) {
+        this.error = error;
+      },
+    },
+  },
+  computed: {
+    loading() {
+      return this.$apollo.queries.content.loading;
+    },
+    errorMessage() {
+      const { message, networkError } = this.error ?? {};
+
+      let reason = message ?? this.$options.i18n.unknownMessage;
+
+      if (networkError && networkError.response) {
+        const { data = {} } = networkError.response;
+        // 400 for a missing ref uses `error`
+        // 404 for missing file uses `message`
+        reason = data.message ?? data.error ?? reason;
+      }
+
+      return sprintf(this.$options.i18n.errorMessageWithReason, { reason });
+    },
   },
   i18n: {
-    title: s__('Pipelines|Pipeline Editor'),
-    description: s__(
-      'Pipelines|We are beginning our work around building the foundation for our dedicated pipeline editor.',
-    ),
-    primaryButtonText: __('Learn more'),
+    unknownMessage: __('Unknown Error'),
+    errorMessageWithReason: s__('Pipelines|CI file could not be loaded: %{reason}'),
   },
 };
 </script>
 
 <template>
-  <gl-empty-state
-    :title="$options.i18n.title"
-    :description="$options.i18n.description"
-    :primary-button-text="$options.i18n.primaryButtonText"
-    primary-button-link="https://about.gitlab.com/direction/verify/pipeline_authoring/"
-  />
+  <div class="gl-mt-4">
+    <gl-alert v-if="error" :dismissible="false" variant="danger">{{ errorMessage }}</gl-alert>
+    <div class="gl-mt-4">
+      <gl-loading-icon v-if="loading" size="lg" />
+      <text-editor v-else v-model="content" />
+    </div>
+  </div>
 </template>

app/views/projects/ci/pipeline_editor/show.html.haml

 - page_title s_('Pipelines|Pipeline Editor')
 
-#js-pipeline-editor
+#js-pipeline-editor{ data: { "ci-config-path": @project.ci_config_path_or_default,
+  "project-path" => @project.full_path,
+  "default-branch" => @project.default_branch,
+} }

locale/gitlab.pot

@@ -19519,6 +19519,9 @@ msgstr ""
 msgid "Pipelines|CI Lint"
 msgstr ""
 
+msgid "Pipelines|CI file could not be loaded: %{reason}"
+msgstr ""
+
 msgid "Pipelines|Child pipeline"
 msgstr ""
 
@@ -19609,9 +19612,6 @@ msgstr ""
 msgid "Pipelines|Trigger user has insufficient permissions to project"
 msgstr ""
 
-msgid "Pipelines|We are beginning our work around building the foundation for our dedicated pipeline editor."
-msgstr ""
-
 msgid "Pipelines|invalid"
 msgstr ""
 

spec/frontend/pipeline_editor/components/text_editor_spec.js

+import { shallowMount } from '@vue/test-utils';
+import EditorLite from '~/vue_shared/components/editor_lite.vue';
+import { mockCiYml } from '../mock_data';
+
+import TextEditor from '~/pipeline_editor/components/text_editor.vue';
+
+describe('~/pipeline_editor/components/text_editor.vue', () => {
+  let wrapper;
+
+  const createComponent = (props = {}, mountFn = shallowMount) => {
+    wrapper = mountFn(TextEditor, {
+      propsData: {
+        value: mockCiYml,
+        ...props,
+      },
+    });
+  };
+
+  const findEditor = () => wrapper.find(EditorLite);
+
+  it('contains an editor', () => {
+    createComponent();
+
+    expect(findEditor().exists()).toBe(true);
+  });
+
+  it('editor contains the value provided', () => {
+    expect(findEditor().props('value')).toBe(mockCiYml);
+  });
+
+  it('editor is readony and configured for .yml', () => {
+    expect(findEditor().props('editorOptions')).toEqual({ readOnly: true });
+    expect(findEditor().props('fileName')).toBe('*.yml');
+  });
+});

spec/frontend/pipeline_editor/graphql/resolvers_spec.js

+import Api from '~/api';
+import { mockProjectPath, mockDefaultBranch, mockCiConfigPath, mockCiYml } from '../mock_data';
+
+import { resolvers } from '~/pipeline_editor/graphql/resolvers';
+
+jest.mock('~/api', () => {
+  return {
+    getRawFile: jest.fn(),
+  };
+});
+
+describe('~/pipeline_editor/graphql/resolvers', () => {
+  describe('Query', () => {
+    describe('blobContent', () => {
+      beforeEach(() => {
+        Api.getRawFile.mockResolvedValue({
+          data: mockCiYml,
+        });
+      });
+
+      afterEach(() => {
+        Api.getRawFile.mockReset();
+      });
+
+      it('resolves lint data with type names', async () => {
+        const result = resolvers.Query.blobContent(null, {
+          projectPath: mockProjectPath,
+          path: mockCiConfigPath,
+          ref: mockDefaultBranch,
+        });
+
+        expect(Api.getRawFile).toHaveBeenCalledWith(mockProjectPath, mockCiConfigPath, {
+          ref: mockDefaultBranch,
+        });
+
+        // eslint-disable-next-line no-underscore-dangle
+        expect(result.__typename).toBe('BlobContent');
+        await expect(result.rawData).resolves.toBe(mockCiYml);
+      });
+    });
+  });
+});

spec/frontend/pipeline_editor/mock_data.js

+export const mockProjectPath = 'user1/project1';
+export const mockDefaultBranch = 'master';
+
+export const mockCiConfigPath = '.gitlab-ci.yml';
+export const mockCiYml = `
+job1:
+  stage: test
+  script: 
+    - echo 'test'
+`;

spec/frontend/pipeline_editor/pipeline_editor_app_spec.js

+import { nextTick } from 'vue';
 import { mount, shallowMount } from '@vue/test-utils';
-import { GlEmptyState } from '@gitlab/ui';
+import { GlAlert, GlLoadingIcon } from '@gitlab/ui';
 
+import { mockProjectPath, mockDefaultBranch, mockCiConfigPath, mockCiYml } from './mock_data';
+import TextEditor from '~/pipeline_editor/components/text_editor.vue';
+import EditorLite from '~/vue_shared/components/editor_lite.vue';
 import PipelineEditorApp from '~/pipeline_editor/pipeline_editor_app.vue';
 
 describe('~/pipeline_editor/pipeline_editor_app.vue', () => {
   let wrapper;
 
-  const createComponent = (mountFn = shallowMount) => {
-    wrapper = mountFn(PipelineEditorApp);
+  const createComponent = ({ props = {}, loading = false } = {}, mountFn = shallowMount) => {
+    wrapper = mountFn(PipelineEditorApp, {
+      propsData: {
+        projectPath: mockProjectPath,
+        defaultBranch: mockDefaultBranch,
+        ciConfigPath: mockCiConfigPath,
+        ...props,
+      },
+      stubs: {
+        TextEditor,
+      },
+      mocks: {
+        $apollo: {
+          queries: {
+            content: {
+              loading,
+            },
+          },
+        },
+      },
+    });
   };
 
-  const findEmptyState = () => wrapper.find(GlEmptyState);
+  const findLoadingIcon = () => wrapper.find(GlLoadingIcon);
+  const findAlert = () => wrapper.find(GlAlert);
+  const findEditor = () => wrapper.find(EditorLite);
 
-  it('contains an empty state', () => {
+  it('displays content', async () => {
     createComponent();
+    wrapper.setData({ content: mockCiYml });
+    await nextTick();
 
-    expect(findEmptyState().exists()).toBe(true);
+    expect(findLoadingIcon().exists()).toBe(false);
+    expect(findEditor().props('value')).toBe(mockCiYml);
   });
 
-  it('contains a text description', () => {
-    createComponent(mount);
+  it('displays a loading icon if the query is loading', async () => {
+    createComponent({ loading: true });
 
-    expect(findEmptyState().text()).toMatchInterpolatedText(
-      'Pipeline Editor We are beginning our work around building the foundation for our dedicated pipeline editor. Learn more',
-    );
+    expect(findLoadingIcon().exists()).toBe(true);
+  });
+
+  describe('when in error state', () => {
+    class MockError extends Error {
+      constructor(message, data) {
+        super(message);
+        if (data) {
+          this.networkError = {
+            response: { data },
+          };
+        }
+      }
+    }
+
+    beforeEach(() => {
+      createComponent(mount);
+    });
+
+    it('shows a generic error', async () => {
+      wrapper.setData({ error: new MockError('An error message') });
+      await nextTick();
+
+      expect(findAlert().text()).toBe('CI file could not be loaded: An error message');
+    });
+
+    it('shows a ref missing error state', async () => {
+      const error = new MockError('Ref missing!', {
+        error: 'ref is missing, ref is empty',
+      });
+
+      wrapper.setData({ error });
+      await nextTick();
+
+      expect(findAlert().text()).toMatch(
+        'CI file could not be loaded: ref is missing, ref is empty',
+      );
+    });
+
+    it('shows a file missing error state', async () => {
+      const error = new MockError('File missing!', {
+        message: 'file not found',
+      });
+
+      wrapper.setData({ error });
+      await nextTick();
+
+      expect(findAlert().text()).toMatch('CI file could not be loaded: file not found');
+    });
   });
 });