Fix platform unit tests by rewiring to support mock-fs

Author: andyleejordan

src/platform.ts

@@ -6,7 +6,9 @@ import * as os from "os";
 import * as path from "path";
 import * as process from "process";
 import { IPowerShellAdditionalExePathSettings } from "./settings";
-import { checkIfFileExists, checkIfDirectoryExists } from "./utils";
+// This uses require so we can rewire it in unit tests!
+// tslint:disable-next-line:no-var-requires
+const utils = require("./utils")
 
 const WindowsPowerShell64BitLabel = "Windows PowerShell (x64)";
 const WindowsPowerShell32BitLabel = "Windows PowerShell (x86)";
@@ -276,7 +278,7 @@ export class PowerShellExeFinder {
         // Find the base directory for MSIX application exe shortcuts
         const msixAppDir = path.join(process.env.LOCALAPPDATA, "Microsoft", "WindowsApps");
 
-        if (!await checkIfDirectoryExists(msixAppDir)) {
+        if (!await utils.checkIfDirectoryExists(msixAppDir)) {
             return null;
         }
 
@@ -319,7 +321,7 @@ export class PowerShellExeFinder {
         const powerShellInstallBaseDir = path.join(programFilesPath, "PowerShell");
 
         // Ensure the base directory exists
-        if (!await checkIfDirectoryExists(powerShellInstallBaseDir)) {
+        if (!await utils.checkIfDirectoryExists(powerShellInstallBaseDir)) {
             return null;
         }
 
@@ -365,7 +367,7 @@ export class PowerShellExeFinder {
 
             // Now look for the file
             const exePath = path.join(powerShellInstallBaseDir, item, "pwsh.exe");
-            if (!await checkIfFileExists(exePath)) {
+            if (!await utils.checkIfFileExists(exePath)) {
                 continue;
             }
 
@@ -491,7 +493,7 @@ class PossiblePowerShellExe implements IPossiblePowerShellExe {
 
     public async exists(): Promise<boolean> {
         if (this.knownToExist === undefined) {
-            this.knownToExist = await checkIfFileExists(this.exePath);
+            this.knownToExist = await utils.checkIfFileExists(this.exePath);
         }
         return this.knownToExist;
     }

test/core/paths.test.ts

@@ -3,7 +3,6 @@
 
 import * as assert from "assert";
 import * as fs from "fs";
-import * as path from "path";
 import * as vscode from "vscode";
 import { IPowerShellExtensionClient } from "../../src/features/ExternalApi";
 import utils = require("../utils");

test/core/platform.test.ts

@@ -5,8 +5,29 @@ import * as assert from "assert";
 import mockFS = require("mock-fs");
 import FileSystem = require("mock-fs/lib/filesystem");
 import * as path from "path";
+import rewire = require("rewire");
 import * as sinon from "sinon";
 import * as platform from "../../src/platform";
+import * as fs from "fs";
+import * as vscode from "vscode";
+
+// We have to rewire the platform module so that mock-fs can be used, as it
+// overrides the fs module but not the vscode.workspace.fs module.
+const platformMock = rewire("../../src/platform");
+
+async function fakeCheckIfFileOrDirectoryExists(targetPath: string | vscode.Uri): Promise<boolean> {
+    try {
+        fs.lstatSync(targetPath instanceof vscode.Uri ? targetPath.fsPath : targetPath);
+        return true;
+    } catch {
+        return false;
+    }
+}
+const utilsMock = {
+    checkIfFileExists: fakeCheckIfFileOrDirectoryExists,
+    checkIfDirectoryExists: fakeCheckIfFileOrDirectoryExists
+}
+platformMock.__set__("utils", utilsMock);
 
 /**
  * Describes a platform on which the PowerShell extension should work,
@@ -469,7 +490,7 @@ function setupTestEnvironment(testPlatform: ITestPlatform) {
 
 describe("Platform module", function () {
     it("Gets the correct platform details", function () {
-        const platformDetails: platform.IPlatformDetails = platform.getPlatformDetails();
+        const platformDetails: platform.IPlatformDetails = platformMock.getPlatformDetails();
         switch (process.platform) {
             case "darwin":
                 assert.strictEqual(
@@ -521,7 +542,7 @@ describe("Platform module", function () {
         }
     });
 
-    describe("Default PowerShell installation", async function () {
+    describe("Default PowerShell installation", function () {
         afterEach(function () {
             sinon.restore();
             mockFS.restore();
@@ -531,7 +552,7 @@ describe("Platform module", function () {
             it(`Finds it on ${testPlatform.name}`, async function () {
                 setupTestEnvironment(testPlatform);
 
-                const powerShellExeFinder = new platform.PowerShellExeFinder(testPlatform.platformDetails);
+                const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails);
 
                 const defaultPowerShell = await powerShellExeFinder.getFirstAvailablePowerShellInstallation();
                 const expectedPowerShell = testPlatform.expectedPowerShellSequence[0];
@@ -545,7 +566,7 @@ describe("Platform module", function () {
             it(`Fails gracefully on ${testPlatform.name}`, async function () {
                 setupTestEnvironment(testPlatform);
 
-                const powerShellExeFinder = new platform.PowerShellExeFinder(testPlatform.platformDetails);
+                const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails);
 
                 const defaultPowerShell = await powerShellExeFinder.getFirstAvailablePowerShellInstallation();
                 assert.strictEqual(defaultPowerShell, undefined);
@@ -563,7 +584,7 @@ describe("Platform module", function () {
             it(`Finds them on ${testPlatform.name}`, async function () {
                 setupTestEnvironment(testPlatform);
 
-                const powerShellExeFinder = new platform.PowerShellExeFinder(testPlatform.platformDetails);
+                const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails);
 
                 const foundPowerShells = await powerShellExeFinder.getAllAvailablePowerShellInstallations();
 
@@ -586,7 +607,7 @@ describe("Platform module", function () {
             it(`Fails gracefully on ${testPlatform.name}`, async function () {
                 setupTestEnvironment(testPlatform);
 
-                const powerShellExeFinder = new platform.PowerShellExeFinder(testPlatform.platformDetails);
+                const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails);
 
                 const foundPowerShells = await powerShellExeFinder.getAllAvailablePowerShellInstallations();
                 assert.strictEqual(foundPowerShells.length, 0);
@@ -626,7 +647,7 @@ describe("Platform module", function () {
                     altWinPSPath = null;
                 }
 
-                const powerShellExeFinder = new platform.PowerShellExeFinder(testPlatform.platformDetails);
+                const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails);
 
                 assert.strictEqual(powerShellExeFinder.fixWindowsPowerShellPath(winPSPath), winPSPath);
 

test/features/RunCode.test.ts

@@ -7,7 +7,6 @@ import * as path from "path";
 import rewire = require("rewire");
 import vscode = require("vscode");
 import utils = require("../utils");
-import { sleep } from "../../src/utils";
 
 // Setup function that is not exported.
 const customViews = rewire("../../src/features/RunCode");