Write job summary in post action

- Save build results in file encoded as JSON
- Read all build results in post action and render as table in job summary

src/job-summary.ts

@@ -0,0 +1,59 @@
+import * as core from '@actions/core'
+import fs from 'fs'
+import path from 'path'
+
+interface BuildResult {
+    get rootProject(): string
+    get requestedTasks(): string
+    get gradleVersion(): string
+    get buildFailed(): boolean
+    get buildScanUri(): string
+}
+
+export function writeJobSummary(): void {
+    const buildResults = loadBuildResults()
+    if (buildResults.length === 0) {
+        core.debug('No Gradle build results found. Summary table will not be generated.')
+    } else {
+        writeSummaryTable(buildResults)
+    }
+}
+
+function loadBuildResults(): BuildResult[] {
+    const buildResultsDir = path.resolve(process.env['RUNNER_TEMP']!, '.build-results')
+    if (!fs.existsSync(buildResultsDir)) {
+        return []
+    }
+
+    return fs.readdirSync(buildResultsDir).map(file => {
+        // Every file in the .build-results dir should be a BuildResults JSON
+        const filePath = path.join(buildResultsDir, file)
+        const content = fs.readFileSync(filePath, 'utf8')
+        return JSON.parse(content) as BuildResult
+    })
+}
+
+function writeSummaryTable(results: BuildResult[]): void {
+    core.summary.addRaw(`| Root Project | Tasks | Gradle Version | Outcome |\n| - | - | - | - |\n`)
+    for (const result of results) {
+        const tableRow = `| ${result.rootProject} \
+                          | ${result.requestedTasks} \
+                          | ${result.gradleVersion} \
+                          | ${renderOutcome(result)} \
+                          |\n`
+        core.summary.addRaw(tableRow)
+    }
+    core.summary.write()
+}
+
+function renderOutcome(result: BuildResult): string {
+    if (result.buildScanUri) {
+        return `[![Gradle Build](https://img.shields.io/badge/Build%20Scan%E2%84%A2-${
+            result.buildFailed ? 'FAILED-red' : 'SUCCESS-brightgreen'
+        }?logo=Gradle)](${result.buildScanUri})`
+    }
+
+    return `![Gradle Build](https://img.shields.io/badge/${
+        result.buildFailed ? 'FAILED-red' : 'SUCCESS-brightgreen'
+    }?logo=Gradle)`
+}

src/post.ts

@@ -1,5 +1,6 @@
 import * as core from '@actions/core'
 import * as setupGradle from './setup-gradle'
+import {writeJobSummary} from './job-summary'
 
 // Catch and log any unhandled exceptions.  These exceptions can leak out of the uploadChunk method in
 // @actions/toolkit when a failed upload closes the file descriptor causing any in-process reads to
@@ -12,6 +13,8 @@ process.on('uncaughtException', e => handleFailure(e))
 export async function run(): Promise<void> {
     try {
         await setupGradle.complete()
+
+        writeJobSummary()
     } catch (error) {
         handleFailure(error)
     }

src/resources/build-result-capture.init.gradle

@@ -33,17 +33,23 @@ def registerCallbacks(buildScanExtension, rootProjectName) {
         }
 
         buildScanPublished { buildScan ->
-            def gradleCommand = rootProjectName + " " + gradle.startParameter.taskNames.join(" ")
+            def buildResultsDir = new File(System.getenv("RUNNER_TEMP"), ".build-results")
+            buildResultsDir.mkdirs()
             
-            // Write job summary to magic file defined by GitHub Actions.
-            def githubSummaryFile = new File(System.getenv("GITHUB_STEP_SUMMARY"))
-            if (buildFailed) {
-                githubSummaryFile << ":x: Gradle Build `${gradleCommand}` [![Gradle Enterprise Build Scan](https://img.shields.io/badge/Gradle%20Enterprise%20Build%20Scan%E2%84%A2-FAILED-red?logo=Gradle)](${buildScan.buildScanUri})"
-            } else {
-                githubSummaryFile << ":white_check_mark: Gradle Build `${gradleCommand}` [![Gradle Enterprise Build Scan](https://img.shields.io/badge/Gradle%20Enterprise%20Build%20Scan%E2%84%A2-SUCCESS-brightgreen?logo=Gradle)](${buildScan.buildScanUri})"
-            }
+            def buildResultsFile = new File(buildResultsDir, System.getenv("GITHUB_ACTION") + System.currentTimeMillis() + ".json")
+
+            def requestedTasks = gradle.startParameter.taskNames.join(" ")
+            def gradleVersion = GradleVersion.current().version
+            def buildScanUri = buildScan.buildScanUri.toASCIIString()
+            def buildResults = [
+                rootProject: rootProjectName, 
+                requestedTasks: requestedTasks,
+                gradleVersion: gradleVersion, 
+                buildFailed: buildFailed, 
+                buildScanUri: buildScanUri
+            ]
+            buildResultsFile << groovy.json.JsonOutput.toJson(buildResults)
 
-            // Send 'set-output' command directly to GitHub Actions via STDOUT.
             println("::set-output name=build-scan-url::${buildScan.buildScanUri}")
         }
     }