Compiler (still) crashes with "Declaration to checkResolvedBlockScopedVariable is undefined"

[felixfbecker]

Similar/same as #27061, but still happening in 3.1.0-dev.20180915.

Introduced in 3.1.0-dev.20180906, last working version was 3.1.0-dev.20180905.

Stack trace:

Debug Failure. Declaration to checkResolvedBlockScopedVariable is undefined

    at checkResolvedBlockScopedVariable (node_modules/typescript/lib/typescript.js:31697:33)
    at resolveNameHelper (node_modules/typescript/lib/typescript.js:31538:25)
    at resolveName (node_modules/typescript/lib/typescript.js:31219:20)
    at getResolvedSymbol (node_modules/typescript/lib/typescript.js:43026:21)
    at checkIdentifier (node_modules/typescript/lib/typescript.js:44474:26)
    at checkExpressionWorker (node_modules/typescript/lib/typescript.js:50599:28)
    at checkExpression (node_modules/typescript/lib/typescript.js:50571:42)
    at checkNonNullExpression (node_modules/typescript/lib/typescript.js:47062:37)
    at checkPropertyAccessExpressionOrQualifiedName (node_modules/typescript/lib/typescript.js:47088:28)
    at checkPropertyAccessExpression (node_modules/typescript/lib/typescript.js:47081:20)

TypeScript Version: 3.1.0-dev.20180915

[Kingwl]

cannot recurrent

[felixfbecker]

@Kingwl I am not saying that code triggers it. I don't know what triggers this, it's a codebase with thousands of lines of code, it could be anything. But the stack trace is real

[Kingwl]

🤷🏻‍♂️

[minestarks]

@RyanCavanaugh I have a quite a few repros of this

Version 3.1.0-dev.20180925

git clone --depth=1 https://github.com/adobe/brackets
cd brackets
tsc --init
tsc --allowJs --checkJs

Error: Debug Failure. Declaration to checkResolvedBlockScopedVariable is undefined
    at checkResolvedBlockScopedVariable (node_modules\typescript\lib\tsc.js:25937:33)
    at resolveNameHelper (node_modules\typescript\lib\tsc.js:25788:25)
    at resolveName (node_modules\typescript\lib\tsc.js:25555:20)
    at resolveEntityName (node_modules\typescript\lib\tsc.js:26243:26)
    at resolveTypeReferenceName (node_modules\typescript\lib\tsc.js:31245:20)
    at getTypeFromTypeReference (node_modules\typescript\lib\tsc.js:31412:30)
    at checkTypeReferenceNode (node_modules\typescript\lib\tsc.js:42928:24)
    at checkSourceElement (node_modules\typescript\lib\tsc.js:45932:28)
    at Object.forEach (node_modules\typescript\lib\tsc.js:169:30)
    at checkUnionOrIntersectionType (node_modules\typescript\lib\tsc.js:42993:16)

[RyanCavanaugh]

Validated 3.1 call stack. Regression from 3.0.

[RyanCavanaugh]

Simplest repro

/**
 * @enum {number}
 */
var foo = { };

/**
 * @type {foo}
 */
var s;

The problem here is that foo is being used as a "type" but we filter out all non-block-scoped declarations, and var is not a block-scoped declaration. I think the filtering is wrong in this case?

Failure here:

        function checkResolvedBlockScopedVariable(result: Symbol, errorLocation: Node): void {
            Debug.assert(!!(result.flags & SymbolFlags.BlockScopedVariable || result.flags & SymbolFlags.Class || result.flags & SymbolFlags.Enum));
            // Block-scoped variables cannot be used before their definition
            const declaration = forEach(result.declarations, d => isBlockOrCatchScoped(d) || isClassLike(d) || (d.kind === SyntaxKind.EnumDeclaration) ? d : undefined);

            if (declaration === undefined) return Debug.fail("Declaration to checkResolvedBlockScopedVariable is undefined");