test: avoid deep comparisons with literals

Comparing any value to any non-RegExp literal or undefined using
strictEqual (or notStrictEqual) passes if and only if deepStrictEqual
(or notDeepStrictEqual, respectively) passes.
Unnecessarily using deep comparisons adds confusion.
This patch adds an ESLint rule that forbids the use of deepStrictEqual
and notDeepStrictEqual when the expected value (i.e., the second
argument) is a non-RegExp literal or undefined.
For reference, an ESTree literal is defined as follows.
extend interface Literal <: Expression {
type: "Literal";
value: string | boolean | null | number | RegExp | bigint;
}
The value `undefined` is an `Identifier` with `name: 'undefined'`.
PR-URL: #40634
Backport-PR-URL: #42021
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Voltrex <mohammadkeyvanzade94@gmail.com>

Author: tniessen

test/.eslintrc.yaml

@@ -13,6 +13,10 @@ rules:
 no-restricted-syntax:
 # Config copied from .eslintrc.js
  - error
+ - selector: "CallExpression:matches([callee.name='deepStrictEqual'], [callee.property.name='deepStrictEqual']):matches([arguments.1.type='Literal']:not([arguments.1.regex]), [arguments.1.type='Identifier'][arguments.1.name='undefined'])"
+message: "Use strictEqual instead of deepStrictEqual for literals or undefined."
+ - selector: "CallExpression:matches([callee.name='notDeepStrictEqual'], [callee.property.name='notDeepStrictEqual']):matches([arguments.1.type='Literal']:not([arguments.1.regex]), [arguments.1.type='Identifier'][arguments.1.name='undefined'])"
+message: "Use notStrictEqual instead of notDeepStrictEqual for literals or undefined."
  - selector: "CallExpression:matches([callee.name='deepStrictEqual'], [callee.property.name='deepStrictEqual'])[arguments.2.type='Literal']"
 message: "Do not use a literal for the third argument of assert.deepStrictEqual()"
  - selector: "CallExpression:matches([callee.name='doesNotThrow'], [callee.property.name='doesNotThrow'])"

test/es-module/test-esm-data-urls.js

@@ -15,7 +15,7 @@ function createBase64URL(mime, body) {
 constplainESMURL=createURL('text/javascript',body);
 constns=awaitimport(plainESMURL);
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default.a,'aaa');
+assert.strictEqual(ns.default.a,'aaa');
 constimporterOfURL=createURL(
 'text/javascript',
 `export {default as default} from ${JSON.stringify(plainESMURL)}`
@@ -35,41 +35,41 @@ function createBase64URL(mime, body) {
 constplainESMURL=createURL('text/javascript',body);
 constns=awaitimport(plainESMURL);
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,plainESMURL);
+assert.strictEqual(ns.default,plainESMURL);
 }
 {
 constbody='export default import.meta.url;';
 constplainESMURL=createURL('text/javascript;charset=UTF-8',body);
 constns=awaitimport(plainESMURL);
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,plainESMURL);
+assert.strictEqual(ns.default,plainESMURL);
 }
 {
 constbody='export default import.meta.url;';
 constplainESMURL=createURL('text/javascript;charset="UTF-8"',body);
 constns=awaitimport(plainESMURL);
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,plainESMURL);
+assert.strictEqual(ns.default,plainESMURL);
 }
 {
 constbody='export default import.meta.url;';
 constplainESMURL=createURL('text/javascript;;a=a;b=b;;',body);
 constns=awaitimport(plainESMURL);
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,plainESMURL);
+assert.strictEqual(ns.default,plainESMURL);
 }
 {
 constns=awaitimport('data:application/json;foo="test,"this"',
 {assert: {type: 'json'}});
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,'this');
+assert.strictEqual(ns.default,'this');
 }
 {
 constns=awaitimport(`data:application/json;foo=${
 encodeURIComponent('test,')
 },0`,{assert: {type: 'json'}});
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default,0);
+assert.strictEqual(ns.default,0);
 }
 {
 awaitassert.rejects(async()=>
@@ -84,14 +84,14 @@ function createBase64URL(mime, body) {
 constplainESMURL=createURL('application/json',body);
 constns=awaitimport(plainESMURL,{assert: {type: 'json'}});
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default.x,1);
+assert.strictEqual(ns.default.x,1);
 }
 {
 constbody='{"default": 2}';
 constplainESMURL=createURL('application/json',body);
 constns=awaitimport(plainESMURL,{assert: {type: 'json'}});
 assert.deepStrictEqual(Object.keys(ns),['default']);
-assert.deepStrictEqual(ns.default.default,2);
+assert.strictEqual(ns.default.default,2);
 }
 {
 constbody='null';

test/js-native-api/test_conversions/test.js

@@ -118,10 +118,10 @@ assert.deepStrictEqual(new String(''), test.toObject(''));
 assert.deepStrictEqual(newNumber(0),test.toObject(0));
 assert.deepStrictEqual(newNumber(Number.NaN),test.toObject(Number.NaN));
 assert.deepStrictEqual(newObject(testSym),test.toObject(testSym));
-assert.notDeepStrictEqual(test.toObject(false),false);
-assert.notDeepStrictEqual(test.toObject(true),true);
-assert.notDeepStrictEqual(test.toObject(''),'');
-assert.notDeepStrictEqual(test.toObject(0),0);
+assert.notStrictEqual(test.toObject(false),false);
+assert.notStrictEqual(test.toObject(true),true);
+assert.notStrictEqual(test.toObject(''),'');
+assert.notStrictEqual(test.toObject(0),0);
 assert.ok(!Number.isNaN(test.toObject(Number.NaN)));
 
 assert.strictEqual(test.toString(''),'');

test/parallel/test-assert-deep.js

@@ -858,11 +858,13 @@ assert.throws(
 }
 
 assert.throws(
+// eslint-disable-next-line no-restricted-syntax
 ()=>assert.deepStrictEqual(4,'4'),
 {message: `${defaultMsgStart}\n4 !== '4'\n`}
 );
 
 assert.throws(
+// eslint-disable-next-line no-restricted-syntax
 ()=>assert.deepStrictEqual(true,1),
 {message: `${defaultMsgStart}\ntrue !== 1\n`}
 );

test/parallel/test-assert.js

@@ -1243,6 +1243,7 @@ assert.throws(
 {
 letthrew=false;
 try{
+// eslint-disable-next-line no-restricted-syntax
 assert.deepStrictEqual(Array(100).fill(1),'foobar');
 }catch(err){
 threw=true;

test/parallel/test-crypto-hmac.js

@@ -422,8 +422,8 @@ assert.strictEqual(
 }
 {
 consth=crypto.createHmac('sha1','key').update('data');
-assert.deepStrictEqual(h.digest('latin1'),expected);
-assert.deepStrictEqual(h.digest('latin1'),'');
+assert.strictEqual(h.digest('latin1'),expected);
+assert.strictEqual(h.digest('latin1'),'');
 }
 }
 
@@ -440,8 +440,8 @@ assert.strictEqual(
 }
 {
 consth=crypto.createHmac('sha1','key');
-assert.deepStrictEqual(h.digest('latin1'),expected);
-assert.deepStrictEqual(h.digest('latin1'),'');
+assert.strictEqual(h.digest('latin1'),expected);
+assert.strictEqual(h.digest('latin1'),'');
 }
 }
 

test/parallel/test-dns-lookup.js

@@ -137,7 +137,7 @@ dns.lookup('127.0.0.1', {
 family: 4,
 all: false
 },common.mustSucceed((result,addressType)=>{
-assert.deepStrictEqual(result,'127.0.0.1');
+assert.strictEqual(result,'127.0.0.1');
 assert.strictEqual(addressType,4);
 }));
 

test/parallel/test-dns.js

@@ -337,10 +337,10 @@ assert.throws(() => {
 
 {
 dns.resolveMx('foo.onion',function(err){
-assert.deepStrictEqual(err.code,'ENOTFOUND');
-assert.deepStrictEqual(err.syscall,'queryMx');
-assert.deepStrictEqual(err.hostname,'foo.onion');
-assert.deepStrictEqual(err.message,'queryMx ENOTFOUND foo.onion');
+assert.strictEqual(err.code,'ENOTFOUND');
+assert.strictEqual(err.syscall,'queryMx');
+assert.strictEqual(err.hostname,'foo.onion');
+assert.strictEqual(err.message,'queryMx ENOTFOUND foo.onion');
 });
 }
 

test/parallel/test-error-serdes.js

@@ -64,5 +64,5 @@ assert.strictEqual(cycle(Function), '[Function: Function]');
 }
 
 serializeError(newDynamicError());
-assert.deepStrictEqual(called,true);
+assert.strictEqual(called,true);
 }

test/parallel/test-fs-promises-file-handle-chmod.js

@@ -19,7 +19,7 @@ async function validateFilePermission() {
 constfileHandle=awaitopen(filePath,'w+',0o444);
 // File created with r--r--r-- 444
 conststatsBeforeMod=fs.statSync(filePath);
-assert.deepStrictEqual(statsBeforeMod.mode&0o444,0o444);
+assert.strictEqual(statsBeforeMod.mode&0o444,0o444);
 
 letexpectedAccess;
 constnewPermissions=0o765;