Update: improve suggestion testing experience (#12602)

bradzacher · Kai Cataldo · commit 05faebb94345 · 2019-12-20T15:26:06.000-05:00
Previously you had to explicitly pass the exact same value (undefined), which meant either explicitly set `suggestions: undefined`, or omit the property.
I hate writing `undefined`, but I prefer to be explicit in my tests and say "I expect no suggestions".
Now you can pass any falsey, or an empty array, and the rule tester will perform as expected.
diff --git a/lib/rule-tester/rule-tester.js b/lib/rule-tester/rule-tester.js
@@ -596,8 +596,10 @@ class RuleTester {
                         if (hasOwnProperty(error, "suggestions")) {
 
                             // Support asserting there are no suggestions
-                            if (!error.suggestions) {
-                                assert.strictEqual(message.suggestions, error.suggestions, `Error should have no suggestions on error with message: "${message.message}"`);
+                            if (!error.suggestions || (Array.isArray(error.suggestions) && error.suggestions.length === 0)) {
+                                if (Array.isArray(message.suggestions) && message.suggestions.length > 0) {
+                                    assert.fail(`Error should have no suggestions on error with message: "${message.message}"`);
+                                }
                             } else {
                                 assert.strictEqual(Array.isArray(message.suggestions), true, `Error should have an array of suggestions. Instead received "${message.suggestions}" on error with message: "${message.message}"`);
                                 assert.strictEqual(message.suggestions.length, error.suggestions.length, `Error should have ${error.suggestions.length} suggestions. Instead found ${message.suggestions.length} suggestions`);
diff --git a/tests/lib/rule-tester/rule-tester.js b/tests/lib/rule-tester/rule-tester.js
@@ -1018,29 +1018,33 @@ describe("RuleTester", () => {
         });
 
         it("should support explicitly expecting no suggestions", () => {
-            ruleTester.run("suggestions-basic", require("../../fixtures/testers/rule-tester/no-eval"), {
-                valid: [],
-                invalid: [{
-                    code: "eval('var foo');",
-                    errors: [{
-                        suggestions: void 0
-                    }]
-                }]
-            });
-        });
-
-        it("should fail when expecting no suggestions and there are suggestions", () => {
-            assert.throws(() => {
-                ruleTester.run("suggestions-basic", require("../../fixtures/testers/rule-tester/suggestions").basic, {
+            [void 0, null, false, []].forEach(suggestions => {
+                ruleTester.run("suggestions-basic", require("../../fixtures/testers/rule-tester/no-eval"), {
                     valid: [],
                     invalid: [{
-                        code: "var foo;",
+                        code: "eval('var foo');",
                         errors: [{
-                            suggestions: void 0
+                            suggestions
                         }]
                     }]
                 });
-            }, "Error should have no suggestions on error with message: \"Avoid using identifiers named 'foo'.\"");
+            });
+        });
+
+        it("should fail when expecting no suggestions and there are suggestions", () => {
+            [void 0, null, false, []].forEach(suggestions => {
+                assert.throws(() => {
+                    ruleTester.run("suggestions-basic", require("../../fixtures/testers/rule-tester/suggestions").basic, {
+                        valid: [],
+                        invalid: [{
+                            code: "var foo;",
+                            errors: [{
+                                suggestions
+                            }]
+                        }]
+                    });
+                }, "Error should have no suggestions on error with message: \"Avoid using identifiers named 'foo'.\"");
+            });
         });
 
         it("should fail when testing for suggestions that don't exist", () => {
