Load settings from local.settings.json for add sql bindings quickpick (#16957)

* load settings from local.settings.json for add sql bindings quickpick

* cleanup

* addressing comments

extensions/sql-database-projects/src/common/azureFunctionsUtils.ts

@@ -0,0 +1,72 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+import * as fse from 'fs-extra';
+import * as path from 'path';
+import * as vscode from 'vscode';
+import * as utils from './utils';
+import * as constants from './constants';
+import { parseJson } from './parseJson';
+
+/**
+ * Represents the settings in an Azure function project's local.settings.json file
+ */
+export interface ILocalSettingsJson {
+	IsEncrypted?: boolean;
+	Values?: { [key: string]: string };
+	Host?: { [key: string]: string };
+	ConnectionStrings?: { [key: string]: string };
+}
+
+/**
+ * copied and modified from vscode-azurefunctions extension
+ * @param localSettingsPath full path to local.settings.json
+ * @returns settings in local.settings.json. If no settings are found, returns default "empty" settings
+ */
+export async function getLocalSettingsJson(localSettingsPath: string): Promise<ILocalSettingsJson> {
+	if (await fse.pathExists(localSettingsPath)) {
+		const data: string = (await fse.readFile(localSettingsPath)).toString();
+		if (/[^\s]/.test(data)) {
+			try {
+				return parseJson(data);
+			} catch (error) {
+				throw new Error(constants.failedToParse(error.message));
+			}
+		}
+	}
+
+	return {
+		IsEncrypted: false // Include this by default otherwise the func cli assumes settings are encrypted and fails to run
+	};
+}
+
+/**
+ * Gets the Azure Functions project that contains the given file if the project is open in one of the workspace folders
+ * @param filePath file that the containing project needs to be found for
+ * @returns filepath of project or undefined if project couldn't be found
+ */
+export async function getAFProjectContainingFile(filePath: string): Promise<string | undefined> {
+	// get functions csprojs in the workspace
+	const projectPromises = vscode.workspace.workspaceFolders?.map(f => utils.getAllProjectsInFolder(f.uri, '.csproj')) ?? [];
+	const functionsProjects = (await Promise.all(projectPromises)).reduce((prev, curr) => prev.concat(curr), []).filter(p => isFunctionProject(path.dirname(p.fsPath)));
+
+	// look for project folder containing file if there's more than one
+	if (functionsProjects.length > 1) {
+		// TODO: figure out which project contains the file
+		// the new style csproj doesn't list all the files in the project anymore, unless the file isn't in the same folder
+		// so we can't rely on using that to check
+		console.error('need to find which project contains the file ' + filePath);
+		return undefined;
+	} else if (functionsProjects.length === 0) {
+		throw new Error(constants.noAzureFunctionsProjectsInWorkspace);
+	} else {
+		return functionsProjects[0].fsPath;
+	}
+}
+
+// Use 'host.json' as an indicator that this is a functions project
+// copied from verifyIsproject.ts in vscode-azurefunctions extension
+export async function isFunctionProject(folderPath: string): Promise<boolean> {
+	return fse.pathExists(path.join(folderPath, constants.hostFileName));
+}