Consolidate error processing in actions

sources/src/errors.ts

@@ -1,3 +1,5 @@
+import * as core from '@actions/core'
+
 export class PostActionJobFailure extends Error {
     constructor(error: unknown) {
         if (error instanceof Error) {
@@ -9,3 +11,31 @@ export class PostActionJobFailure extends Error {
         }
     }
 }
+
+export function handleMainActionError(error: unknown): void {
+    if (error instanceof AggregateError) {
+        core.setFailed(`Multiple errors returned`)
+        for (const err of error.errors) {
+            core.error(`Error ${error.errors.indexOf(err)}: ${err.message}`)
+            if (err.stack) {
+                core.info(err.stack)
+            }
+        }
+    } else {
+        core.setFailed(String(error))
+        if (error instanceof Error && error.stack) {
+            core.info(error.stack)
+        }
+    }
+}
+
+export function handlePostActionError(error: unknown): void {
+    if (error instanceof PostActionJobFailure) {
+        core.setFailed(String(error))
+    } else {
+        core.warning(`Unhandled error in Gradle post-action - job will continue: ${error}`)
+        if (error instanceof Error && error.stack) {
+            core.info(error.stack)
+        }
+    }
+}