filterProblemsForDocument() lower-case file paths => breaks diagnostics (OSX)

[danielweck]

This is the current code:
https://github.com/angelozerr/tslint-language-service/blob/72a02a2/src/index.ts#L99-L110

        function filterProblemsForDocument(documentPath: string, failures: tslint.RuleFailure[]): tslint.RuleFailure[] {
            let normalizedPath = path.normalize(documentPath);
            // we only show diagnostics targetting this open document, some tslint rule return diagnostics for other documents/files
            let normalizedFiles = new Map<string, string>();
            return failures.filter(each => {
                let fileName = each.getFileName();
                if (!normalizedFiles.has(fileName)) {
                    normalizedFiles.set(fileName, path.normalize(fileName));
                }
                return normalizedFiles.get(fileName) === normalizedPath;
            });
        }

The problem is that let fileName = each.getFileName(); returns lower-case file paths! For example, typically on OSX: /User/myName/etc. becomes /user/myname/etc.. No idea why.

I temporarily fixed this by adding .toLowerCase():
let normalizedPath = path.normalize(documentPath).toLowerCase();
...and just for consistency (not strictly needed):
let fileName = each.getFileName().toLowerCase();

[angelozerr]

@danielweck thanks for your proposition.

@egamma what do you think about this idea?

[danielweck]

PS:
I've added this package.json one-liner (sed) NPM script to fix 'tslint-language-service' after each yarn upgrade (or any Yarn / NPM command that resets / updates node_modules):

sed -i "" "s/let normalizedPath = path\.normalize(documentPath);/let normalizedPath = path.normalize(documentPath).toLowerCase();/g" ./node_modules/tslint-language-service/out/src/index.js

(works on OSX, untested elsewhere)

[egamma]

@angelozerr fixing a file system case sensitivity issue by calling toLowerCase is almost always wrong thing to do, e.g. in a case sensitive file system, there can be a file with a name that is lower case. The typescript server does a lot of effort to handle file systems with different case sensitivity. We should understand why there is a case sensitivity issue on OS X. We should reproduce this is on OS X and see what is the root cause.

@danielweck what are the steps to reproduce this problem?

[danielweck]

Sure, create the files below inside a folder called TSLint-test (make sure to use Upper case characters), and run the following commands:

• cd TSLint-test
• npm install
• npm run lint (tslint errors are reported in the console, as expected)
• npm run lint:full (same errors, as expected)
• load the folder with VSCode (i.e. code .), open index.ts, wait a second or two ... no TSLint errors are reported in the "PROBLEMS" tab!
• npm run lintfix
• close the VSCode app, re-load the folder (i.e. code .), and re-open index.ts => now the TSLint errors show up (red squiggly lines).

---

index.ts

const txt = 'test'; // TSLINT ERROR (should be double-quotes)
console.log(txt); // TSLINT ERROR (use of console API forbidden)

---

tslint.json

{
  "extends": "tslint:recommended"
}

---

tsconfig.json

{
  "languageServiceEnabled": true,
  "compilerOptions": {
    "target": "es2015",
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "./dist/",
    "plugins": [
      {
        "name": "tslint-language-service",
        "alwaysShowRuleFailuresAsWarnings": false,
        "ignoreDefinitionFiles": true,
        "configFile": "./tslint.json",
        "disableNoUnusedVariableRule": true
      }
    ],
    "rootDir": "./",
    "rootDirs": [
      "./"
    ],
    "baseUrl": "."
  },
  "exclude": [
    "node_modules"
  ],
  "include": [
    "./*.ts"
  ]
}

---

package.json

{
  "name": "tslint-lang-service-filepath-lowercase-bug",
  "version": "0.0.0-alpha0",
  "dependencies": {
  },
  "devDependencies": {
    "tslint": "latest",
    "tslint-language-service": "latest",
    "typescript": "latest"
  },
  "main": "./index.js",
  "types": "./dist/index.d.js",
  "bin": {
    "index": "./dist/index.js"
  },
  "files": [
    "dist/**/*"
  ],
  "scripts": {
    "clean": "rm -rf ./dist",
    "lintfix": "sed -i \"\" \"s/let normalizedPath = path\\.normalize(documentPath);/let normalizedPath = path.normalize(documentPath).toLowerCase();/g\" ./node_modules/tslint-language-service/out/src/index.js",
    "prelint": "npm run clean",
    "lint": "tslint -c \"./tslint.json\" \"./*.ts\"",
    "prelint:full": "npm run clean",
    "lint:full": "tslint --project \"./tsconfig.json\" -c \"./tslint.json\" \"./*.ts\"",
    "pretsc": "npm run clean && npm run lint:full",
    "tsc": "tsc -p \"./tsconfig.json\""
  }
}