Breaking: disallow SourceCode#getComments() in RuleTester (refs #14744)

lib/rule-tester/rule-tester.js

@@ -55,6 +55,8 @@ const ajv = require("../shared/ajv")({ strictDefaults: true });
 const espreePath = require.resolve("espree");
 const parserSymbol = Symbol.for("eslint.RuleTester.parser");
 
+const { SourceCode } = require("../source-code");
+
 //------------------------------------------------------------------------------
 // Typedefs
 //------------------------------------------------------------------------------
@@ -284,6 +286,17 @@ function wrapParser(parser) {
     };
 }
 
+/**
+ * Function to replace `SourceCode.prototype.getComments`.
+ * @returns {void}
+ * @throws {Error} Deprecation message.
+ */
+function getCommentsDeprecation() {
+    throw new Error(
+        "`SourceCode#getComments()` is deprecated and will be removed in a future major version. Use `getCommentsBefore()`, `getCommentsAfter()`, and `getCommentsInside()`."
+    );
+}
+
 //------------------------------------------------------------------------------
 // Public Interface
 //------------------------------------------------------------------------------
@@ -607,7 +620,16 @@ class RuleTester {
             validate(config, "rule-tester", id => (id === ruleName ? rule : null));
 
             // Verify the code.
-            const messages = linter.verify(code, config, filename);
+            const { getComments } = SourceCode.prototype;
+            let messages;
+
+            try {
+                SourceCode.prototype.getComments = getCommentsDeprecation;
+                messages = linter.verify(code, config, filename);
+            } finally {
+                SourceCode.prototype.getComments = getComments;
+            }
+
             const fatalErrorMessage = messages.find(m => m.fatal);
 
             assert(!fatalErrorMessage, `A fatal parsing error occurred: ${fatalErrorMessage && fatalErrorMessage.message}`);

tests/lib/rule-tester/rule-tester.js

@@ -2462,4 +2462,37 @@ describe("RuleTester", () => {
 
     });
 
+    describe("SourceCode#getComments()", () => {
+        const useGetCommentsRule = {
+            create: context => ({
+                Program(node) {
+                    const sourceCode = context.getSourceCode();
+
+                    sourceCode.getComments(node);
+                }
+            })
+        };
+
+        it("should throw if called from a valid test case", () => {
+            assert.throws(() => {
+                ruleTester.run("use-get-comments", useGetCommentsRule, {
+                    valid: [""],
+                    invalid: []
+                });
+            }, /`SourceCode#getComments\(\)` is deprecated/u);
+        });
+
+        it("should throw if called from an invalid test case", () => {
+            assert.throws(() => {
+                ruleTester.run("use-get-comments", useGetCommentsRule, {
+                    valid: [],
+                    invalid: [{
+                        code: "",
+                        errors: [{}]
+                    }]
+                });
+            }, /`SourceCode#getComments\(\)` is deprecated/u);
+        });
+    });
+
 });