Use sub-directory for 'setup-gradle' dist

To prepare for converting the 'dependency-submission' action into Typescript,
we move the 'setup-gradle' entry points and outputs into a sub-directory.

sources/src/setup-gradle/main.ts

@@ -0,0 +1,37 @@
+import * as core from '@actions/core'
+
+import * as setupGradle from '../setup-gradle'
+import * as execution from '../execution'
+import * as provisioner from '../provision'
+import * as layout from '../repository-layout'
+import * as params from '../input-params'
+
+/**
+ * The main entry point for the action, called by Github Actions for the step.
+ */
+export async function run(): Promise<void> {
+    try {
+        // Configure Gradle environment (Gradle User Home)
+        await setupGradle.setup()
+
+        // Download and install Gradle if required
+        const executable = await provisioner.provisionGradle()
+
+        // Only execute if arguments have been provided
+        const args: string[] = params.getArguments()
+        if (args.length > 0) {
+            const buildRootDirectory = layout.buildRootDirectory()
+            await execution.executeGradleBuild(executable, buildRootDirectory, args)
+        }
+    } catch (error) {
+        core.setFailed(String(error))
+        if (error instanceof Error && error.stack) {
+            core.info(error.stack)
+        }
+    }
+
+    // Explicit process.exit() to prevent waiting for hanging promises.
+    process.exit()
+}
+
+run()

sources/src/setup-gradle/post.ts

@@ -0,0 +1,35 @@
+import * as core from '@actions/core'
+import * as setupGradle from '../setup-gradle'
+import {PostActionJobFailure} from '../errors'
+
+// 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
+// throw an uncaught exception.  Instead of failing this action, just warn.
+process.on('uncaughtException', e => handleFailure(e))
+
+/**
+ * The post-execution entry point for the action, called by Github Actions after completing all steps for the Job.
+ */
+export async function run(): Promise<void> {
+    try {
+        await setupGradle.complete()
+    } catch (error) {
+        if (error instanceof PostActionJobFailure) {
+            core.setFailed(String(error))
+        } else {
+            handleFailure(error)
+        }
+    }
+
+    // Explicit process.exit() to prevent waiting for promises left hanging by `@actions/cache` on save.
+    process.exit()
+}
+
+function handleFailure(error: unknown): void {
+    core.warning(`Unhandled error in Gradle post-action - job will continue: ${error}`)
+    if (error instanceof Error && error.stack) {
+        core.info(error.stack)
+    }
+}
+
+run()