reafctor: prefer to use context.sourceCode and add tests for getSourc…

…eCode()

docs/src/extend/custom-rules.md

@@ -128,6 +128,7 @@ The `context` object has the following properties:
 * `physicalFilename`: (`string`) When linting a file, it provides the full path of the file on disk without any code block information. When linting text, it provides the value passed to `—stdin-filename` or `<text>` if not specified.
 * `cwd`: (`string`) The `cwd` option passed to the [Linter](../integrate/nodejs-api#linter). It is a path to a directory that should be considered the current working directory.
 * `options`: (`array`) An array of the [configured options](../use/configure/rules) for this rule. This array does not include the rule severity (see the [dedicated section](#accessing-options-passed-to-a-rule)).
+* `sourceCode`: (`object`) A `SourceCode` object that you can use to work with the source that was passed to ESLint (see [Accessing the Source Code](#accessing-the-source-code)).
 * `settings`: (`object`) The [shared settings](../use/configure/configuration-files#adding-shared-settings) from the configuration.
 * `parserPath`: (`string`) The name of the `parser` from the configuration.
 * `parserServices`: (`object`) Contains parser-provided services for rules. The default parser does not provide any services. However, if a rule is intended to be used with a custom parser, it could use `parserServices` to access anything provided by that parser. (For example, a TypeScript parser could provide the ability to get the computed type of a given node.)
@@ -151,7 +152,6 @@ Additionally, the `context` object has the following methods:
 * `getPhysicalFilename()`: (**Deprecated:** Use `context.physicalFilename` instead.) When linting a file, it returns the full path of the file on disk without any code block information. When linting text, it returns the value passed to `—stdin-filename` or `<text>` if not specified.
 * `getScope()`: (**Deprecated:** Use `SourceCode#getScope(node)` instead.) Returns the [scope](./scope-manager-interface#scope-interface) of the currently-traversed node. This information can be used to track references to variables.
 * `getSourceCode()`: (**Deprecated:** Use `context#sourceCode` instead.) Returns a `SourceCode` object that you can use to work with the source that was passed to ESLint (see [Accessing the Source Code](#accessing-the-source-code)).
-* `sourceCode`: Returns a `SourceCode` object that you can use to work with the source that was passed to ESLint (see [Accessing the Source Code](#accessing-the-source-code)).
 * `markVariableAsUsed(name)`: (**Deprecated:** Use `SourceCode#markVariableAsUsed(name, node)` instead.)  Marks a variable with the given name in the current scope as used. This affects the [no-unused-vars](../rules/no-unused-vars) rule. Returns `true` if a variable with the given name was found and marked as used, otherwise `false`.
 * `report(descriptor)`. Reports a problem in the code (see the [dedicated section](#reporting-problems)).
 

lib/linter/linter.js

@@ -902,7 +902,7 @@ const BASE_TRAVERSAL_CONTEXT = Object.freeze(
         (contextInfo, methodName) =>
             Object.assign(contextInfo, {
                 [methodName](...args) {
-                    return this.getSourceCode()[DEPRECATED_SOURCECODE_PASSTHROUGHS[methodName]](...args);
+                    return this.sourceCode[DEPRECATED_SOURCECODE_PASSTHROUGHS[methodName]](...args);
                 }
             }),
         {}

tests/lib/linter/linter.js

@@ -116,6 +116,7 @@ describe("Linter", () => {
 
         it("has all the `parent` properties on nodes when the rule listeners are created", () => {
             const spy = sinon.spy(context => {
+                assert.strictEqual(context.getSourceCode(), context.sourceCode);
                 const ast = context.sourceCode.ast;
 
                 assert.strictEqual(ast.body[0].parent, ast);
@@ -3780,6 +3781,7 @@ var a = "test2";
                             const sourceCode = context.sourceCode;
                             const comments = sourceCode.getAllComments();
 
+                            assert.strictEqual(context.getSourceCode(), sourceCode);
                             assert.strictEqual(1, comments.length);
 
                             const foo = getVariable(scope, "foo");
@@ -5436,6 +5438,7 @@ var a = "test2";
                             const sourceCode = context.sourceCode;
                             const comments = sourceCode.getAllComments();
 
+                            assert.strictEqual(context.getSourceCode(), sourceCode);
                             assert.strictEqual(2, comments.length);
 
                             const foo = getVariable(scope, "foo");
@@ -8962,6 +8965,7 @@ describe("Linter with FlatConfigArray", () => {
 
             it("should have all the `parent` properties on nodes when the rule visitors are created", () => {
                 const spy = sinon.spy(context => {
+                    assert.strictEqual(context.getSourceCode(), context.sourceCode);
                     const ast = context.sourceCode.ast;
 
                     assert.strictEqual(ast.body[0].parent, ast);
@@ -11617,6 +11621,7 @@ describe("Linter with FlatConfigArray", () => {
                                                 const sourceCode = context.sourceCode;
                                                 const comments = sourceCode.getAllComments();
 
+                                                assert.strictEqual(context.getSourceCode(), sourceCode);
                                                 assert.strictEqual(2, comments.length);
 
                                                 const foo = getVariable(scope, "foo");
@@ -13899,6 +13904,7 @@ var a = "test2";
                                                     const sourceCode = context.sourceCode;
                                                     const comments = sourceCode.getAllComments();
 
+                                                    assert.strictEqual(context.getSourceCode(), sourceCode);
                                                     assert.strictEqual(1, comments.length);
 
                                                     const foo = getVariable(scope, "foo");