feat: Add trend indicator (#323)

* refactor: Adds folders for more clarity

* feat: Adds feature to show trend indicator by comparing json summaries

* feat: Adjusts target in report

* chore: adjusts output design and adds test export

* tests: Fixes tests

* docs: Includes docs for the feature

README.md

@@ -75,15 +75,16 @@ This action requires the `pull-request: write` permission to add a comment to yo
 
 ### Options
 
-| Option               | Description                                                                                                                                  | Default                                                                       |
-| -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- |
-| `working-directory`  | The main path to search for coverage- and configuration files (adjusting this is especially useful in monorepos).                            | `./`                                                                          |
-| `json-summary-path`  | The path to the json summary file.                                                                                                           | `${working-directory}/coverage/coverage-summary.json`                         |
-| `json-final-path`    | The path to the json final file.                                                                                                             | `${working-directory}/coverage/coverage-final.json`                           |
-| `vite-config-path`   | The path to the vite config file. Will check the same paths as vite and vitest                                                               | Checks pattern `${working-directory}/vite[st].config.{t\|mt\|ct\|j\|mj\|cj}s` |
-| `github-token`       | A GitHub access token with permissions to write to issues (defaults to `secrets.GITHUB_TOKEN`).                                              | `${{ github.token }}`                                                         |
-| `file-coverage-mode` | Defines how file-based coverage is reported. Possible values are `all`, `changes` or `none`.                                                 | `changes`                                                                     |
-| `name`               | Give the report a custom name. This is useful if you want multiple reports for different test suites within the same PR. Needs to be unique. | ''                                                                            |
+| Option                      | Description                                                                                                                                                                | Default                                                                       |
+| --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- |
+| `working-directory`         | The main path to search for coverage- and configuration files (adjusting this is especially useful in monorepos).                                                          | `./`                                                                          |
+| `json-summary-path`         | The path to the json summary file.                                                                                                                                         | `${working-directory}/coverage/coverage-summary.json`                         |
+| `json-final-path`           | The path to the json final file.                                                                                                                                           | `${working-directory}/coverage/coverage-final.json`                           |
+| `vite-config-path`          | The path to the vite config file. Will check the same paths as vite and vitest                                                                                             | Checks pattern `${working-directory}/vite[st].config.{t\|mt\|ct\|j\|mj\|cj}s` |
+| `github-token`              | A GitHub access token with permissions to write to issues (defaults to `secrets.GITHUB_TOKEN`).                                                                            | `${{ github.token }}`                                                         |
+| `file-coverage-mode`        | Defines how file-based coverage is reported. Possible values are `all`, `changes` or `none`.                                                                               | `changes`                                                                     |
+| `name`                      | Give the report a custom name. This is useful if you want multiple reports for different test suites within the same PR. Needs to be unique.                               | ''                                                                            |
+| `json-summary-compare-path` | The path to the json summary file to compare against. If given, will display a trend indicator and the difference in the summary. Respects the `working-directory` option. | undefined                                                                     |
 
 #### File Coverage Mode
 
@@ -142,6 +143,69 @@ With the above configuration, the report would appear as follows:
 
 If no thresholds are defined, the status will display as '🔵'.
 
+### Coverage Trend Indicator
+
+By using the `json-summary-compare-path` option, the action will display both a trend indicator and the coverage difference in the summary. This feature is particularly useful for tracking changes between the main branch and a previous run.
+
+![Screenshot of the action-result showcasing the trend indicator](./docs/coverage-report-trend-indicator.png)
+
+The most straightforward method to obtain the comparison file within a pull request is to run the tests and generate the coverage for the target branch within a matrix job:
+
+```yml
+name: "Test"
+on:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        branch:
+          - ${{ github.head_ref }}
+          - "main"
+
+    permissions:
+      # Required to checkout the code
+      contents: read
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ matrix.branch }}
+      - name: "Install Node"
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+      - name: "Install Deps"
+        run: npm install
+      - name: "Test"
+        run: npx vitest --coverage.enabled true
+      - name: "Upload Coverage"
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-${{ matrix.branch }}
+          path: coverage
+
+  report-coverage:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Download Coverage Artifacts"
+        uses: actions/download-artifact@v4
+        with:
+          name: coverage-${{ github.head_ref }}
+          path: coverage
+      - uses: actions/download-artifact@v4
+        with:
+          name: coverage-main
+          path: coverage-main
+      - name: "Report Coverage"
+        uses: davelosert/vitest-coverage-report-action@v2
+        with:
+          json-summary-compare-path: coverage-main/coverage-summary.json
+```
+
 ### Workspaces
 
 If you're using a monorepo with [Vitest Workspaces](https://vitest.dev/guide/workspace.html) and running Vitest from your project's root, Vitest will disregard the `coverage` property in individual project-level Vite configuration files. This is because some [configuration options](https://vitest.dev/guide/workspace.html#configuration), such as coverage, apply to the entire workspace and are not allowed in a project config.

action.yml

@@ -13,14 +13,17 @@ inputs:
       required: false
       description: 'The path to the json summary file. Uses "coverage/coverage-summary.json" by default.'
       default: coverage/coverage-summary.json
-  file-coverage-mode:
+  json-summary-compare-path:
       required: false
-      description: 'How to show summary for files coverage. Uses "changes" by default.'
-      default: changes
+      description: 'The path to the json summary file of the previous run to get trend indicators.'
   json-final-path:
       required: false
       description: 'The path to the json final file. Uses "coverage/coverage-final.json" by default.'
       default: coverage/coverage-final.json
+  file-coverage-mode:
+      required: false
+      description: 'How to show summary for files coverage. Uses "changes" by default.'
+      default: changes
   working-directory:
       required: false
       description: 'Custom working directory'

package.json

@@ -7,6 +7,7 @@
   "scripts": {
     "test": "vitest",
     "test:coverage": "vitest run --coverage.enabled true",
+    "test:export": "npx ts-node test/exportTestTable.ts",
     "build": "rm -rf dist && node esbuild.cjs",
     "start": "npm run build && node dist/index.js",
     "typecheck": "npx tsc --noEmit"

src/icons.ts

@@ -2,6 +2,10 @@ const icons = {
   red: '🔴',
   green: '🟢',
   blue: '🔵',
+	increase: '⬆️',
+	decrease: '⬇️',
+	equal: '🟰',
+	target: '🎯'
 }
 
 export {

src/index.ts

@@ -1,27 +1,34 @@
-import { generateSummaryTableHtml } from './generateSummaryTableHtml.js';
-import { parseVitestJsonFinal, parseVitestJsonSummary } from './parseJsonReports.js';
+import { FileCoverageMode } from './inputs/FileCoverageMode.js'
+import { generateFileCoverageHtml } from './report/generateFileCoverageHtml.js';
+import { generateHeadline } from './report/generateHeadline.js';
+import { generateSummaryTableHtml } from './report/generateSummaryTableHtml.js';
+import { getPullChanges } from './inputs/getPullChanges.js';
+import { parseVitestJsonFinal, parseVitestJsonSummary } from './inputs/parseJsonReports.js';
+import { readOptions } from './inputs/options.js';
+import { RequestError } from '@octokit/request-error'
 import { writeSummaryToPR } from './writeSummaryToPR.js';
 import * as core from '@actions/core';
 import * as github from '@actions/github';
-import { RequestError } from '@octokit/request-error'
-import { generateFileCoverageHtml } from './generateFileCoverageHtml.js';
-import { getPullChanges } from './getPullChanges.js';
-import { FileCoverageMode } from './FileCoverageMode.js'
-import { readOptions } from './options.js';
-import { generateHeadline } from './generateHeadline.js';
 
 const run = async () => {
 	const {
 		fileCoverageMode,
 		jsonFinalPath,
 		jsonSummaryPath,
+		jsonSummaryComparePath,
 		name,
 		thresholds,
 		workingDirectory
 	} = await readOptions();
 
 	const jsonSummary = await parseVitestJsonSummary(jsonSummaryPath);
-	const tableData = generateSummaryTableHtml(jsonSummary.total, thresholds);
+
+	let jsonSummaryCompare;
+	if(jsonSummaryComparePath) {
+		jsonSummaryCompare = await parseVitestJsonSummary(jsonSummaryComparePath);
+	}
+
+	const tableData = generateSummaryTableHtml(jsonSummary.total, thresholds, jsonSummaryCompare?.total);
 	const summary = core.summary
 		.addHeading(generateHeadline({ workingDirectory, name }), 2)
 		.addRaw(tableData)

src/getPullChanges.ts → src/inputs/getPullChanges.ts

@@ -56,4 +56,3 @@ export async function getPullChanges(fileCoverageMode: FileCoverageMode): Promis
 		core.endGroup()
 	}
 }
-

src/getViteConfigPath.test.ts → src/inputs/getViteConfigPath.test.ts

@@ -7,6 +7,7 @@ describe("getViteConfigPath", () => {
   const mockWorkingDirectory = path.resolve(
     __dirname,
     "..",
+		'..',
     "test",
     "mockConfig"
   );

src/options.ts → src/inputs/options.ts

@@ -14,6 +14,13 @@ async function readOptions() {
 	const jsonSummaryPath = path.resolve(workingDirectory, core.getInput('json-summary-path'));
 	const jsonFinalPath = path.resolve(workingDirectory, core.getInput('json-final-path'));
 
+
+  const jsonSummaryCompareInput = core.getInput('json-summary-compare-path');
+	let jsonSummaryComparePath;
+	if(jsonSummaryCompareInput) {
+		jsonSummaryComparePath = path.resolve(workingDirectory, jsonSummaryCompareInput);
+	}
+
 	const name = core.getInput('name');
 
   // ViteConfig is optional, as it is only required for thresholds. If no vite config is provided, we will not include thresholds in the final report.
@@ -24,9 +31,10 @@ async function readOptions() {
 		fileCoverageMode,
 		jsonFinalPath,
 		jsonSummaryPath,
+		jsonSummaryComparePath,
 		name,
 		thresholds,
-		workingDirectory
+		workingDirectory,
 	}
 }
 

src/parseCoverageThresholds.test.ts → src/inputs/parseCoverageThresholds.test.ts

@@ -9,7 +9,7 @@ vi.mock('@actions/core', async (importOriginal) => ({
 }));
 
 describe('generateTableData', () => {
-  const mockConfigPath = path.resolve(__dirname, '..', 'test', 'mockConfig');
+  const mockConfigPath = path.resolve(__dirname, '..', '..', 'test', 'mockConfig');
   const getConfig = (configName: string) => path.resolve(mockConfigPath, configName)
 
   it('returns no thresholds if config file can not be found.', async (): Promise<void> => {

src/parseCoverageThresholds.ts → src/inputs/parseCoverageThresholds.ts

@@ -1,7 +1,7 @@
 import path from 'node:path';
 import * as core from '@actions/core';
 import { promises as fs } from 'fs';
-import { Thresholds } from './types/Threshold';
+import { Thresholds } from '../types/Threshold';
 
 const regex100 = /100"?\s*:\s*true/;
 const regexStatements = /statements\s*:\s*(\d+)/;

src/parseJsonReports.ts → src/inputs/parseJsonReports.ts

@@ -1,8 +1,8 @@
 import { readFile } from 'node:fs/promises';
 import * as core from '@actions/core';
 import path from 'node:path';
-import { JsonFinal } from './types/JsonFinal';
-import { JsonSummary } from './types/JsonSummary';
+import { JsonFinal } from '../types/JsonFinal';
+import { JsonSummary } from '../types/JsonSummary';
 import { stripIndent } from 'common-tags';
 
 const parseVitestCoverageReport = async <type extends JsonSummary | JsonFinal>(jsonPath: string): Promise<type> => {

src/generateFileCoverageHtml.test.ts → src/report/generateFileCoverageHtml.test.ts

@@ -1,11 +1,11 @@
-import { createJsonFinalEntry } from './types/JsonFinalMockFactory';
+import { createJsonFinalEntry } from '../types/JsonFinalMockFactory';
 import { generateFileCoverageHtml } from './generateFileCoverageHtml';
-import { getTableLine } from '../test/queryHelper';
-import { JsonFinal } from './types/JsonFinal';
-import { JsonSummary } from './types/JsonSummary';
-import { createMockCoverageReport, createMockJsonSummary, createMockReportNumbers } from './types/JsonSummaryMockFactory';
+import { getTableLine } from '../../test/queryHelper';
+import { JsonFinal } from '../types/JsonFinal';
+import { JsonSummary } from '../types/JsonSummary';
+import { createMockCoverageReport, createMockJsonSummary, createMockReportNumbers } from '../types/JsonSummaryMockFactory';
 import { describe, it, expect } from 'vitest';
-import { FileCoverageMode } from './FileCoverageMode';
+import { FileCoverageMode } from '../inputs/FileCoverageMode';
 import * as path from 'path';
 
 const workspacePath = process.cwd();

src/generateFileCoverageHtml.ts → src/report/generateFileCoverageHtml.ts

@@ -1,11 +1,10 @@
 import * as path from 'path'
-import * as core from '@actions/core'
 import { generateBlobFileUrl } from './generateFileUrl'
 import { LineRange, getUncoveredLinesFromStatements } from './getUncoveredLinesFromStatements'
-import { JsonFinal } from './types/JsonFinal'
-import { JsonSummary } from './types/JsonSummary'
+import { JsonFinal } from '../types/JsonFinal'
+import { JsonSummary } from '../types/JsonSummary'
 import { oneLine } from 'common-tags'
-import { FileCoverageMode } from './FileCoverageMode'
+import { FileCoverageMode } from '../inputs/FileCoverageMode'
 
 type FileCoverageInputs = {
 	jsonSummary: JsonSummary;