sourceFile duplication for TypedRule

[andy-hanson]

Bug Report

• TSLint version: master
• TypeScript version: 2.1.4 (the one in package.json)
• Running TSLint via: ./bin/tslint --test test/rules/my-rule

TypeScript code being linted

export class Rule extends Lint.Rules.TypedRule {
    /* tslint:disable:object-literal-sort-keys */
    public static metadata: Lint.IRuleMetadata = {
        ruleName: "my-rule",
        description: "",
        optionsDescription: "Not configurable.",
        options: null,
        optionExamples: ["true"],
        type: "functionality",
        typescriptOnly: false,
    };
    /* tslint:enable:object-literal-sort-keys */

    public applyWithProgram(sourceFile: ts.SourceFile, langSvc: ts.LanguageService): Lint.RuleFailure[] {
        console.log(sourceFile === langSvc.getProgram().getSourceFile(sourceFile.fileName));
        return [];
    }
}

Actual behavior

Prints false.

Expected behavior

Prints true. The source file used for linting should be the same as the one used for the program.
I want to write a rule that uses the type checker to get information about nodes as I recurse. I can't do that if it uses a different AST.

[nchen63]

Is the AST different or are the sourceFile objects different references?

[andy-hanson]

Looks like they're completely separate. Added this to the top of applyWithProgram in noForInArrayRule.ts:

const langSvcSourceFile = langSvc.getProgram().getSourceFile(sourceFile.fileName);
console.log(sourceFile === langSvcSourceFile);
console.log(sourceFile.statements[0] === langSvcSourceFile.statements[0]);
process.exit(0);

Both lines print false.

[nchen63]

But the getText() and individual offsets would all be the same right? The === is a reference comparison so I don't think you can use that for these objects that are created at different times

[ghost]

Since it's the same file being parsed twice, the two separate source files should have identical contents.