feat(fs): statement to verify if a file exist or not (#98)

Co-authored-by: Puria Nafisi Azizi <[email protected]>

pkg/fs/src/plugin.ts

@@ -46,6 +46,15 @@ const readJSON = async (safePath: string) => {
 	return JSON.parse(str);
 };
 
+const checkFileExists = async (safePath: string) => {
+	try {
+		await fspkg.stat(safePath);
+	} catch {
+		return false;
+	}
+	return true;
+}
+
 const p = new Plugin();
 
 /**
@@ -155,4 +164,30 @@ export const listDirectoryContent = p.new(['path'], 'list directory content', as
 	return ctx.pass(result);
 });
 
+/**
+ * @internal
+ */
+export const verifyFileExists = p.new(['path'], 'verify file exists', async (ctx) => {
+	const unsafe = ctx.fetch('path');
+	if (typeof unsafe !== 'string') return ctx.fail('path must be string');
+
+	const { filepath, error } = resolveFilepath(unsafe);
+	if (!filepath) return ctx.fail(error);
+	if (!(await checkFileExists(filepath))) return ctx.fail('no such file or directory: '+filepath);
+	return ctx.pass(null);
+});
+
+/**
+ * @internal
+ */
+export const verifyFileDoesNotExist = p.new(['path'], 'verify file does not exist', async (ctx) => {
+	const unsafe = ctx.fetch('path');
+	if (typeof unsafe !== 'string') return ctx.fail('path must be string');
+
+	const { filepath, error } = resolveFilepath(unsafe);
+	if (!filepath) return ctx.fail(error);
+	if (await checkFileExists(filepath)) return ctx.fail('file or directory found under: '+filepath);
+	return ctx.pass(null);
+});
+
 export const fs = p;

pkg/fs/test/e2e.ts

@@ -46,4 +46,74 @@ test.serial('Read verbatim file', async (t) => {
         content:"Hello World!\n",
         filename: "test.txt"
     });
-});
+});
+
+test.serial('path not a string', async (t) => {
+	process.env['FILES_DIR'] = "./test";
+	const slangroom = new Slangroom(fs);
+	const fn = slangroom.execute(READ, {
+		data: {
+			filename: {
+				"path": "test.txt"
+			}
+		},
+	});
+	const error = await t.throwsAsync(fn);
+	t.is((error as Error).message, 'path must be string');
+});
+
+test.serial('File exists', async (t) => {
+	const verifyExists = `Rule unknown ignore
+Given I send path 'filename' and verify file exists
+Given I have a 'string' named 'filename'
+Then print the 'filename'
+Then print the string 'the file exists'
+`
+	process.env['FILES_DIR'] = "./test";
+	const slangroom = new Slangroom(fs);
+	const resultExists = slangroom.execute(verifyExists, {
+		data: {
+			filename: "test.txt"
+		},
+	});
+	const res = await resultExists;
+	t.deepEqual(res.result, {
+		filename: 'test.txt',
+		output: ["the_file_exists"]
+	});
+	const resultNotExists = slangroom.execute(verifyExists, {
+		data: {
+			filename: "test_not_exist.txt"
+		},
+	});
+	const error = await t.throwsAsync(resultNotExists);
+	t.is((error as Error).message, 'no such file or directory: test/test_not_exist.txt');
+});
+
+test.serial('File does not exist', async (t) => {
+	const verifyDoesNotExists = `Rule unknown ignore
+Given I send path 'filename' and verify file does not exist
+Given I have a 'string' named 'filename'
+Then print the 'filename'
+Then print the string 'the file does not exist'
+`
+	process.env['FILES_DIR'] = "./test";
+	const slangroom = new Slangroom(fs);
+	const resultExists = slangroom.execute(verifyDoesNotExists, {
+		data: {
+			filename: "test.txt"
+		},
+	});
+	const error = await t.throwsAsync(resultExists);
+	t.is((error as Error).message, 'file or directory found under: test/test.txt');
+	const resultNotExists = slangroom.execute(verifyDoesNotExists, {
+		data: {
+			filename: "test_not_exist.txt"
+		},
+	});
+	const res = await await resultNotExists;
+	t.deepEqual(res.result, {
+		filename: 'test_not_exist.txt',
+		output: ["the_file_does_not_exist"]
+	});
+});