refactor(fs): rename read functions to be more specific, add docstrings (aws#5713)

## Problem
Follow up from: aws#5689

## Solution
- rename 'readFileAsString' to 'readFileText' since this function
assumes a text file (utf-8) encoding.
- Add missing doc strings to copy and exist within fs wrapper. 

---

<!--- REMINDER: Ensure that your PR meets the guidelines in
CONTRIBUTING.md -->

License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

---------

Co-authored-by: Justin M. Keyes <[email protected]>

Author: Hweinstock

packages/amazonq/test/unit/amazonqGumby/humanInTheLoopManager.test.ts

@@ -36,7 +36,7 @@ describe('HumanInTheLoopManager', async function () {
         )
         const outputPathResult = path.join(outputDirectoryPath, 'pom.xml')
         assertEqualPaths(newPomFilePath.fsPath, outputPathResult)
-        const newPomFileContents = await fs.readFileAsString(newPomFilePath.path)
+        const newPomFileContents = await fs.readFileText(newPomFilePath.path)
         assert.strictEqual(
             stripStringWhitespace(newPomFileContents),
             stripStringWhitespace(`<?xml version="1.0" encoding="UTF-8"?>

packages/amazonq/test/unit/validation.test.ts

@@ -23,7 +23,7 @@ describe('package validations', function () {
      */
     it('has synced contributes.icons with core/package.json', async function () {
         const corePackageJson = JSON.parse(
-            await fs.readFileAsString(path.resolve(__dirname, '../../../../core/package.json'))
+            await fs.readFileText(path.resolve(__dirname, '../../../../core/package.json'))
         )
         assert.deepStrictEqual(packageJson.contributes.icons, corePackageJson.contributes.icons)
     })

packages/core/src/amazonq/lsp/lspController.ts

@@ -133,7 +133,7 @@ export class LspController {
     }
 
     async getFileSha384(filePath: string): Promise<string> {
-        const fileBuffer = await fs.readFile(filePath)
+        const fileBuffer = await fs.readFileBytes(filePath)
         const hash = crypto.createHash('sha384')
         hash.update(fileBuffer)
         return hash.digest('hex')

packages/core/src/auth/credentials/sharedCredentials.ts

@@ -230,15 +230,15 @@ async function loadConfigFile(configUri?: vscode.Uri): Promise<ReturnType<typeof
         return []
     }
 
-    return parseIni(await fs.readFileAsString(configUri), configUri)
+    return parseIni(await fs.readFileText(configUri), configUri)
 }
 
 async function loadCredentialsFile(credentialsUri?: vscode.Uri): Promise<ReturnType<typeof parseIni>> {
     if (!credentialsUri || !(await fs.exists(credentialsUri))) {
         return []
     }
 
-    return parseIni(await fs.readFileAsString(credentialsUri), credentialsUri)
+    return parseIni(await fs.readFileText(credentialsUri), credentialsUri)
 }
 
 /**

packages/core/src/auth/sso/server.ts

@@ -218,7 +218,7 @@ export class AuthSSOServer {
 
     private async loadResource(res: http.ServerResponse, resourcePath: string) {
         try {
-            const file = await fs.readFile(resourcePath)
+            const file = await fs.readFileBytes(resourcePath)
             res.writeHead(200)
             res.end(file)
         } catch (e) {

packages/core/src/awsService/cdk/explorer/cdkProject.ts

@@ -18,7 +18,7 @@ export interface CdkAppLocation {
 }
 
 export async function getApp(location: CdkAppLocation): Promise<CdkApp> {
-    const constructTree = JSON.parse(await fs.readFileAsString(location.treeUri)) as ConstructTree
+    const constructTree = JSON.parse(await fs.readFileText(location.treeUri)) as ConstructTree
 
     return { location, constructTree }
 }

packages/core/src/awsService/ec2/sshKeyPair.ts

@@ -68,7 +68,7 @@ export class SshKeyPair {
     }
 
     public async getPublicKey(): Promise<string> {
-        const contents = await fs.readFileAsString(this.publicKeyPath)
+        const contents = await fs.readFileText(this.publicKeyPath)
         return contents
     }
 

packages/core/src/awsService/iot/commands/createPolicy.ts

@@ -66,7 +66,7 @@ export async function getPolicyDocument(): Promise<Uint8Array | undefined> {
 
     let data: Uint8Array
     try {
-        data = await fs.readFile(policyLocation.fsPath)
+        data = await fs.readFileBytes(policyLocation.fsPath)
     } catch (e) {
         getLogger().error('Failed to read policy document: %s', e)
         void showViewLogsMessage(localize('AWS.iot.createPolicy.error', 'Failed to read policy document'))

packages/core/src/codewhisperer/service/transformByQ/humanInTheLoopManager.ts

@@ -64,7 +64,7 @@ export class HumanInTheLoopManager {
     }
 
     public getDependencyListXmlOutput = async () =>
-        await fs.readFileAsString(path.join(this.tmpDependencyListDir, this.localPathToXmlDependencyList))
+        await fs.readFileText(path.join(this.tmpDependencyListDir, this.localPathToXmlDependencyList))
 
     public createPomFileCopy = async (outputDirectoryPath: string, pomFileVirtualFileReference: vscode.Uri) => {
         const newPomCopyRef = await createPomCopy(outputDirectoryPath, pomFileVirtualFileReference, 'pom.xml')

packages/core/src/codewhisperer/service/transformByQ/transformApiHandler.ts

@@ -177,7 +177,7 @@ export async function stopJob(jobId: string) {
 }
 
 export async function uploadPayload(payloadFileName: string, uploadContext?: UploadContext) {
-    const buffer = Buffer.from(await fs.readFile(payloadFileName))
+    const buffer = Buffer.from(await fs.readFileBytes(payloadFileName))
     const sha256 = getSha256(buffer)
 
     throwIfCancelled()