add a read() function

.changeset/tall-spies-yell.md

@@ -0,0 +1,5 @@
+---
+"using-temporary-files": minor
+---
+
+added a read() function

README.md

@@ -21,6 +21,7 @@ await usingTemporaryFiles(async ({ path, add, addDirectory, remove }) => {
   path("."); // full path to the temporary directory
   path("file.txt"); // full path to a particular file
   await add("file.txt", "content"); // add a file
+  const text = await read("file.txt" /*, encoding (optional) */); // read the contents of a file
   await addDirectory("dir"); // add a directory
   await remove("file.txt"); // remove a file
 });

src/using-temporary-files.js

@@ -41,6 +41,14 @@ function createRemoveFunction(basePath) {
 	};
 }
 
+function createReadFunction(basePath) {
+	return async function read(filePath, encoding = "utf8") {
+		const fullPath = nodePath.join(basePath, filePath);
+
+		return fs.readFile(fullPath, encoding);
+	};
+}
+
 export async function usingTemporaryFiles(...callbacks) {
 	const baseDirectory = DEBUG
 		? nodePath.resolve(process.cwd(), "./")
@@ -56,7 +64,7 @@ export async function usingTemporaryFiles(...callbacks) {
 				add: createAddFunction(temporaryDirectory),
 				remove: createRemoveFunction(temporaryDirectory),
 				addDirectory: createAddDirectoryFunction(temporaryDirectory),
-
+				read: createReadFunction(temporaryDirectory),
 				path(...relativePaths) {
 					return nodePath.join(temporaryDirectory, ...relativePaths);
 				},

test/using-temporary-files.test.js

@@ -27,6 +27,17 @@ describe("usingTemporaryFiles", () => {
 		expect(timesCallbackCalled).toBe(1);
 	});
 
+	it("read a file", async () => {
+		let timesCallbackCalled = 0;
+		await usingTemporaryFiles(async ({ add, read }) => {
+			timesCallbackCalled++;
+			await add("file.txt", "Hello, world!");
+			expect(await read("file.txt")).toBe("Hello, world!");
+		});
+
+		expect(timesCallbackCalled).toBe(1);
+	});
+
 	it("add a directory", async () => {
 		let timesCallbackCalled = 0;
 		await usingTemporaryFiles(async ({ path, addDirectory }) => {