From c7b97e2c0da5a5a5b2d0f0c039325786e01532f8 Mon Sep 17 00:00:00 2001
From: hkobew <hkobew@amazon.com>
Date: Fri, 24 Jan 2025 12:32:49 -0500
Subject: [PATCH] refactor: move tryFunctions to core and include tests

---
 packages/core/src/amazonq/lsp/util.ts         | 17 -----------
 packages/core/src/shared/lsp/lspResolver.ts   |  3 +-
 .../core/src/shared/lsp/manifestResolver.ts   |  3 +-
 packages/core/src/shared/utilities/tsUtils.ts | 17 +++++++++++
 .../src/test/shared/utilities/tsUtils.test.ts | 28 +++++++++++++++++++
 5 files changed, 49 insertions(+), 19 deletions(-)
 create mode 100644 packages/core/src/test/shared/utilities/tsUtils.test.ts

diff --git a/packages/core/src/amazonq/lsp/util.ts b/packages/core/src/amazonq/lsp/util.ts
index 3829f643e79..f0a384db115 100644
--- a/packages/core/src/amazonq/lsp/util.ts
+++ b/packages/core/src/amazonq/lsp/util.ts
@@ -26,20 +26,3 @@ export async function lspSetupStage<T>(
         return result
     })
 }
-
-/**
- * Try Functions in the order presented and return the first returned result. If none return, throw the final error.
- * @param functions non-empty list of functions to try.
- * @returns
- */
-export async function tryFunctions<Result>(functions: (() => Promise<Result>)[]): Promise<Result> {
-    let currentError: Error = new Error('No functions provided')
-    for (const func of functions) {
-        try {
-            return await func()
-        } catch (e) {
-            currentError = e as Error
-        }
-    }
-    throw currentError
-}
diff --git a/packages/core/src/shared/lsp/lspResolver.ts b/packages/core/src/shared/lsp/lspResolver.ts
index 5903aa1bc6c..26043eb1d25 100644
--- a/packages/core/src/shared/lsp/lspResolver.ts
+++ b/packages/core/src/shared/lsp/lspResolver.ts
@@ -13,7 +13,8 @@ import { TargetContent, logger, LspResult, LspVersion, Manifest } from './types'
 import { getApplicationSupportFolder } from '../vscode/env'
 import { createHash } from '../crypto'
 import request from '../request'
-import { lspSetupStage, tryFunctions } from '../../amazonq/lsp/util'
+import { lspSetupStage } from '../../amazonq/lsp/util'
+import { tryFunctions } from '../utilities/tsUtils'
 
 export class LanguageServerResolver {
     constructor(
diff --git a/packages/core/src/shared/lsp/manifestResolver.ts b/packages/core/src/shared/lsp/manifestResolver.ts
index 1cc8ed647c8..82e90596507 100644
--- a/packages/core/src/shared/lsp/manifestResolver.ts
+++ b/packages/core/src/shared/lsp/manifestResolver.ts
@@ -9,7 +9,8 @@ import { RetryableResourceFetcher } from '../resourcefetcher/httpResourceFetcher
 import { Timeout } from '../utilities/timeoutUtils'
 import globals from '../extensionGlobals'
 import { Manifest } from './types'
-import { lspSetupStage, tryFunctions } from '../../amazonq/lsp/util'
+import { lspSetupStage } from '../../amazonq/lsp/util'
+import { tryFunctions } from '../utilities/tsUtils'
 
 const logger = getLogger('lsp')
 
diff --git a/packages/core/src/shared/utilities/tsUtils.ts b/packages/core/src/shared/utilities/tsUtils.ts
index e4fbf5a2b3f..80d7736f7e0 100644
--- a/packages/core/src/shared/utilities/tsUtils.ts
+++ b/packages/core/src/shared/utilities/tsUtils.ts
@@ -94,6 +94,23 @@ export function createFactoryFunction<T extends new (...args: any[]) => any>(cto
     return (...args) => new ctor(...args)
 }
 
+/**
+ * Try Functions in the order presented and return the first returned result. If none return, throw the final error.
+ * @param functions non-empty list of functions to try.
+ * @returns
+ */
+export async function tryFunctions<Result>(functions: (() => Promise<Result>)[]): Promise<Result> {
+    let currentError: Error = new Error('No functions provided')
+    for (const func of functions) {
+        try {
+            return await func()
+        } catch (e) {
+            currentError = e as Error
+        }
+    }
+    throw currentError
+}
+
 type NoSymbols<T> = { [Property in keyof T]: Property extends symbol ? never : Property }[keyof T]
 export type InterfaceNoSymbol<T> = Pick<T, NoSymbols<T>>
 /**
diff --git a/packages/core/src/test/shared/utilities/tsUtils.test.ts b/packages/core/src/test/shared/utilities/tsUtils.test.ts
new file mode 100644
index 00000000000..bb75a8c436e
--- /dev/null
+++ b/packages/core/src/test/shared/utilities/tsUtils.test.ts
@@ -0,0 +1,28 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { tryFunctions } from '../../../shared/utilities/tsUtils'
+import assert from 'assert'
+
+describe('tryFunctions', function () {
+    it('should return the result of the first function that returns', async function () {
+        const f1 = () => Promise.reject('f1')
+        const f2 = () => Promise.resolve('f2')
+        const f3 = () => Promise.reject('f3')
+
+        assert.strictEqual(await tryFunctions([f1, f2, f3]), 'f2')
+    })
+
+    it('if all reject, then should throw final error', async function () {
+        const f1 = () => Promise.reject('f1')
+        const f2 = () => Promise.reject('f2')
+        const f3 = () => Promise.reject('f3')
+
+        await assert.rejects(
+            async () => await tryFunctions([f1, f2, f3]),
+            (e) => e === 'f3'
+        )
+    })
+})