Expose snapshot directory through test.meta

Fixes #1984.

Co-authored-by: Mark Wubben <mark@novemberborn.net>

docs/01-writing-tests.md

@@ -267,14 +267,19 @@ test('context is unicorn', t => {
 });
 ```
 
-## Retrieving test meta data
+## Retrieving test metadata
 
-Helper files can determine the filename of the test being run by reading `test.meta.file`.  This eliminates the need to pass `__filename` from the test to helpers.
+Access data about the currently loaded test file run by reading `test.meta`.
+
+Available properties:
+
+* `file`: path to the test file
+* `snapshotDirectory`: directory where snapshots are stored
 
 ```js
 const test = require('ava');
 
-console.log('Test currently being run: ', test.meta.file);
+console.log('Test file currently being run:', test.meta.file);
 ```
 
 ## Reusing test logic through macros

index.d.ts

@@ -760,6 +760,9 @@ export interface TodoDeclaration {
 export interface MetaInterface {
 	/** Path to the test file being executed. */
 	file: string;
+
+	/** Directory where snapshots are stored. */
+	snapshotDirectory: string;
 }
 
 /** Call to declare a test, or chain to declare hooks or test modifiers */

lib/runner.js

@@ -54,7 +54,11 @@ class Runner extends Emittery {
 		let hasStarted = false;
 		let scheduledStart = false;
 		const meta = Object.freeze({
-			file: options.file
+			file: options.file,
+			get snapshotDirectory() {
+				const {file, snapshotDir: fixedLocation, projectDir} = options;
+				return snapshotManager.determineSnapshotDir({file, fixedLocation, projectDir});
+			}
 		});
 		this.chain = createChain((metadata, testArgs) => { // eslint-disable-line complexity
 			if (hasStarted) {

lib/snapshot-manager.js

@@ -11,6 +11,7 @@ const md5Hex = require('md5-hex');
 const convertSourceMap = require('convert-source-map');
 const slash = require('slash');
 const writeFileAtomic = require('write-file-atomic');
+const mem = require('mem');
 
 const concordanceOptions = require('./concordance-options').snapshotManager;
 
@@ -388,26 +389,7 @@ class Manager {
 	}
 }
 
-function determineSnapshotDir({file, fixedLocation, projectDir}) {
-	const testDir = path.dirname(file);
-	if (fixedLocation) {
-		const relativeTestLocation = path.relative(projectDir, testDir);
-		return path.join(fixedLocation, relativeTestLocation);
-	}
-
-	const parts = new Set(path.relative(projectDir, testDir).split(path.sep));
-	if (parts.has('__tests__')) {
-		return path.join(testDir, '__snapshots__');
-	}
-
-	if (parts.has('test') || parts.has('tests')) { // Accept tests, even though it's not in the default test patterns
-		return path.join(testDir, 'snapshots');
-	}
-
-	return testDir;
-}
-
-function resolveSourceFile(file) {
+const resolveSourceFile = mem(file => {
 	const testDir = path.dirname(file);
 	const buffer = tryRead(file);
 	if (!buffer) {
@@ -423,12 +405,32 @@ function resolveSourceFile(file) {
 	}
 
 	return file;
-}
+});
+
+const determineSnapshotDir = mem(({file, fixedLocation, projectDir}) => {
+	const testDir = path.dirname(resolveSourceFile(file));
+	if (fixedLocation) {
+		const relativeTestLocation = path.relative(projectDir, testDir);
+		return path.join(fixedLocation, relativeTestLocation);
+	}
+
+	const parts = new Set(path.relative(projectDir, testDir).split(path.sep));
+	if (parts.has('__tests__')) {
+		return path.join(testDir, '__snapshots__');
+	}
+
+	if (parts.has('test') || parts.has('tests')) { // Accept tests, even though it's not in the default test patterns
+		return path.join(testDir, 'snapshots');
+	}
+
+	return testDir;
+}, {cacheKey: ([{file}]) => file});
+
+exports.determineSnapshotDir = determineSnapshotDir;
 
 function load({file, fixedLocation, projectDir, recordNewSnapshots, updating}) {
-	const sourceFile = resolveSourceFile(file);
-	const dir = determineSnapshotDir({file: sourceFile, fixedLocation, projectDir});
-	const relFile = path.relative(projectDir, sourceFile);
+	const dir = determineSnapshotDir({file, fixedLocation, projectDir});
+	const relFile = path.relative(projectDir, resolveSourceFile(file));
 	const name = path.basename(relFile);
 	const reportFile = `${name}.md`;
 	const snapFile = `${name}.snap`;

package-lock.json

@@ -5105,6 +5105,15 @@
 			"integrity": "sha512-s8UhlNe7vPKomQhC1qFelMokr/Sc3AgNbso3n74mVPA5LTZwkB9NlXf4XPamLxJE8h0gh73rM94xvwRT2CVInw==",
 			"dev": true
 		},
+		"map-age-cleaner": {
+			"version": "0.1.3",
+			"resolved": "https://registry.npmjs.org/map-age-cleaner/-/map-age-cleaner-0.1.3.tgz",
+			"integrity": "sha512-bJzx6nMoP6PDLPBFmg7+xRKeFZvFboMrGlxmNj9ClvX53KrmvM5bXFXEWjbz4cz1AFn+jWJ9z/DJSz7hrs0w3w==",
+			"dev": true,
+			"requires": {
+				"p-defer": "^1.0.0"
+			}
+		},
 		"map-cache": {
 			"version": "0.2.2",
 			"resolved": "https://registry.npmjs.org/map-cache/-/map-cache-0.2.2.tgz",
@@ -5165,6 +5174,24 @@
 				"safe-buffer": "^5.1.2"
 			}
 		},
+		"mem": {
+			"version": "6.0.1",
+			"resolved": "https://registry.npmjs.org/mem/-/mem-6.0.1.tgz",
+			"integrity": "sha512-uIRYASflIsXqvKe+7aXbLrydaRzz4qiK6amqZDQI++eRtW3UoKtnDcGeCAOREgll7YMxO5E4VB9+3B0LFmy96g==",
+			"dev": true,
+			"requires": {
+				"map-age-cleaner": "^0.1.3",
+				"mimic-fn": "^3.0.0"
+			},
+			"dependencies": {
+				"mimic-fn": {
+					"version": "3.0.0",
+					"resolved": "https://registry.npmjs.org/mimic-fn/-/mimic-fn-3.0.0.tgz",
+					"integrity": "sha512-PiVO95TKvhiwgSwg1IdLYlCTdul38yZxZMIcnDSFIBUm4BNZha2qpQ4GpJ++15bHoKDtrW2D69lMfFwdFYtNZQ==",
+					"dev": true
+				}
+			}
+		},
 		"memory-fs": {
 			"version": "0.2.0",
 			"resolved": "https://registry.npmjs.org/memory-fs/-/memory-fs-0.2.0.tgz",
@@ -5938,6 +5965,12 @@
 			"resolved": "https://registry.npmjs.org/p-cancelable/-/p-cancelable-1.1.0.tgz",
 			"integrity": "sha512-s73XxOZ4zpt1edZYZzvhqFa6uvQc1vwUa0K0BdtIZgQMAJj9IbebH+JkgKZc9h+B05PKHLOTl4ajG1BmNrVZlw=="
 		},
+		"p-defer": {
+			"version": "1.0.0",
+			"resolved": "https://registry.npmjs.org/p-defer/-/p-defer-1.0.0.tgz",
+			"integrity": "sha1-n26xgvbJqozXQwBKfU+WsZaw+ww=",
+			"dev": true
+		},
 		"p-event": {
 			"version": "4.1.0",
 			"resolved": "https://registry.npmjs.org/p-event/-/p-event-4.1.0.tgz",

package.json

@@ -116,6 +116,7 @@
 		"esm": "^3.2.25",
 		"execa": "^4.0.0",
 		"get-stream": "^5.1.0",
+		"mem": "^6.0.1",
 		"nyc": "^15.0.1",
 		"p-event": "^4.1.0",
 		"proxyquire": "^2.1.3",

test-tap/api.js

@@ -30,12 +30,12 @@ function apiCreator(options = {}) {
 	return instance;
 }
 
-test('test.meta.file', t => {
-	const api = apiCreator();
+test('test.meta', t => {
+	const api = apiCreator({snapshotDir: 'snapshot-fixture'});
 
-	return api.run({files: [path.join(__dirname, 'fixture/meta.js')]})
+	return api.run({files: [path.join(__dirname, 'fixture', 'meta.js')]})
 		.then(runStatus => {
-			t.is(runStatus.stats.passedTests, 2);
+			t.is(runStatus.stats.passedTests, 3);
 		});
 });
 

test-tap/fixture/meta.js

@@ -1,9 +1,14 @@
 const {default: test, meta} = require('../..');
 
+test('meta is test.meta', t => {
+	t.is(meta, test.meta);
+});
+
 test('meta.file', t => {
 	t.is(meta.file, __filename);
 });
 
-test('test.meta.file', t => {
-	t.is(test.meta.file, __filename);
+test('meta.snapshotDirectory', t => {
+	t.regex(meta.snapshotDirectory, /snapshot-fixture/);
 });
+