Inconsistency in getDocumentHighlights for import aliases

[leeavital]

For the file:

import fs = require('fs');
import ws = fs.writeStream;

getDocumentHighlights will not find that the fs on line 1 is the same as the one on line 2.

But for the file:

import fs = require('fs');
var ws = fs.writeStream;

---

I wrote a small program to demonstrate the problem.

var ts = require('typescript');
var fs = require('fs');

var source = fs.readFileSync('test.ts').toString();
var sourceFile = ts.createSourceFile('test.ts', source, 1, false);

var host = {
  getCompilationSettings: function() {
      return {
          noResolve: true,
          target: ts.ScriptTarget.ES5
      };
  },
  getCurrentDirectory: function() {
    return '';
  },
  getDefaultLibFileName: function() {
    return "lib.d.ts"
  },
  getScriptFileNames: function() {
    return ['test.ts'];
  },
  getScriptIsOpen: function() {
    return true
  },
  getScriptVersion: function() {
    return "1"
  },
  getScriptSnapshot: function() {
    return {
      getLength: function() {
        return source.length;
      },
      getLineStartPositions: function () {
        return ts.computeLineStarts(source);
      },
      getText: function(start, end) {
        return source.substring(start, end);
      }
    };
  }
};

var documentRegistry = ts.createDocumentRegistry();
var languageServices = ts.createLanguageService(host, documentRegistry);

var importFS  = sourceFile.statements[0];
var highlights = languageServices.getDocumentHighlights('test.ts', importFS.name.pos + 1, ['test.ts']);
console.log(highlights[0].highlightSpans.length);

When test.ts contains the first example, it outputs 1. When test.ts contains the second example, it outputs 2.

[DanielRosenwasser]

I assume this also means find-references and rename is also not working in this scenario.

[jkillian]

There seem to be some related funny issues going on. When calling getDocumentHighlights on the position of the hello variable declaration in the following code snippet:

// Incorrect case:

class HelloWorld {
    constructor(public name: string) { }
    sayHello() {
        return `Hello, ${this.name}!`;
    }
};

let hello = new HelloWorld("TSLint");
hello.sayHello();

only the declaration is returned and not the usage on the next line. However, in the following code snippet, both uses are returned, correctly:

// Correct case:

class HelloWorld {
    constructor(public name: string) { }
    sayHello() {
        return `Hello, ${this.name}!`;
    }
};

if (true) {
    let hello = new HelloWorld("TSLint");
    hello.sayHello();
}

Also strangely, Sublime will correctly show both references in both cases.

I've been trying to figure out the root cause but haven't been able to yet. I did notice that in the getReferencesInNode function the array of possible positions contains exactly the two actual positions in both the incorrect and correct case. However, there is a difference when finding the relatedSymbol:

var referenceSymbol = typeChecker.getSymbolAtLocation(referenceLocation);
if (referenceSymbol) {
    var referenceSymbolDeclaration = referenceSymbol.valueDeclaration;
    var shorthandValueSymbol = typeChecker.getShorthandAssignmentValueSymbol(referenceSymbolDeclaration);
    var relatedSymbol = getRelatedSymbol(searchSymbols, referenceSymbol, referenceLocation);
    // NOTE (added for the Github issue):
    // relatedSymbol is undefined here in incorrect case, defined in the correct case
    if (relatedSymbol) {
        var referencedSymbol = getReferencedSymbol(relatedSymbol);
        referencedSymbol.references.push(getReferenceEntryFromNode(referenceLocation));
    }
    else if (!(referenceSymbol.flags & 67108864 /* Transient */) && searchSymbols.indexOf(shorthandValueSymbol) >= 0) {
        var referencedSymbol = getReferencedSymbol(shorthandValueSymbol);
        referencedSymbol.references.push(getReferenceEntryFromNode(referenceSymbolDeclaration.name));
    }
}

(Related to palantir/tslint#570)

[DanielRosenwasser]

@jkillian I'm not able to reproduce the error:

it's likely unrelated to the issue filed here, so if you're still seeing it, can you file a separate bug?

[jkillian]

@DanielRosenwasser Created a new issue from my previous comment with a few details added: #4560

[jkillian]

@leeavital The issue comes from this code:

getScriptSnapshot: function() {
    return {
      getLength: function() {
        return source.length;
      },
      getLineStartPositions: function () {
        return ts.computeLineStarts(source);
      },
      getText: function(start, end) {
        return source.substring(start, end);
      }
    };
  }

getScriptSnapshot can request snapshots for files other than source, so only returning code form source causes things to happen incorrectly.

[jkillian]

My apologies, I think this is still a bug. I had assumed that our incorrect usage of the language services was the issue, but it doesn't seem like that's the case. FindReferences in Sublime doesn't mark both references. In addition, this fourslash test fails:

/// <reference path='fourslash.ts' />

////import [|fs|] = require('fs');
////import ws = [|fs|].writeStream;

let ranges = test.ranges()
for (let range of ranges) {
    goTo.position(range.start);

    verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false);
}

(related palantir/tslint#325)

[adidahiya]

@DanielRosenwasser Any updates on this? Is the fix fairly involved?

[DanielRosenwasser]

I'm honestly not sure, I'll try to find some time to work on this soon.

[DanielRosenwasser]

I wonder if this is related to #5501 or #4970.

[mhegazy]

@jkillian is this still an issue? i believe it has been fixed in latest.

[jkillian]

Verified that this is fixed in the latest nightly, thanks! (palantir/tslint#1294) Feel free to close this issue

[mhegazy]

thanks!