check @type tag on require

Author: sandersn

src/compiler/checker.ts

@@ -2390,13 +2390,30 @@ namespace ts {
                 const immediate = resolveExternalModuleName(node, isVariableDeclaration(node)
                     ? (getFirstPropertyAccessExpression(node.initializer!) as CallExpression).arguments[0]
                     : getExternalModuleImportEqualsDeclarationExpression(node));
-                const resolved = resolveExternalModuleSymbol(immediate);
-                if (isVariableDeclaration(node) && node.initializer && isPropertyAccessExpression(node.initializer)) {
-                    // TODO: Relies on old code in resolveCallExpression that special-cases `require("x")`
-                    return isIdentifier(node.initializer.name)
-                        ? getPropertyOfType(checkExpression(node.initializer.expression), node.initializer.name.escapedText)
-                        : undefined;
+                if (isVariableDeclaration(node)) {
+                    const typeTag = getJSDocTypeTag(node);
+                    if (node.initializer && isPropertyAccessExpression(node.initializer)) {
+                        if (!isIdentifier(node.initializer.name))
+                            return undefined;
+                        // TODO: Relies on old code in resolveCallExpression that special-cases `require("x")`
+                        const original = getPropertyOfType(checkExpression(node.initializer.expression), node.initializer.name.escapedText);
+                        if (typeTag && original) {
+                            const symbol: TransientSymbol = cloneSymbol(original) as TransientSymbol
+                            symbol.type = getTypeFromTypeNode(typeTag.typeExpression);
+                            return symbol;
+                        }
+                        // TODO: Might still want to resolveExternalModuleSymbol here?
+                        return original;
+                    }
+                    else if (typeTag && immediate) {
+                        // TODO: This is basically wrong.
+                        const symbol: TransientSymbol = cloneSymbol(immediate) as TransientSymbol
+                        symbol.type = getTypeFromTypeNode(typeTag.typeExpression);
+                        return symbol;
+                    }
+                    return resolveExternalModuleSymbol(immediate);
                 }
+                const resolved = resolveExternalModuleSymbol(immediate);
                 markSymbolOfAliasDeclarationIfTypeOnly(node, immediate, resolved, /*overwriteEmpty*/ false);
                 return resolved;
             }
@@ -32773,6 +32790,12 @@ namespace ts {
             const symbol = getSymbolOfNode(node);
             if (/*isBindingElement(node) && */isRequireVariableDeclaration(node, /*requireStringLiteralLikeArgument*/ true) && symbol.flags & SymbolFlags.Alias) {
                 checkAliasSymbol(node);
+                const typeTag = getJSDocTypeTag(node);
+                const initializer = node.initializer;
+                if (typeTag) {
+                    const type = getTypeFromTypeNode(typeTag.typeExpression);
+                    checkTypeAssignableToAndOptionallyElaborate(checkExpressionCached(initializer), type, node, initializer, /*headMessage*/ undefined);
+                }
                 return;
             }
 

tests/baselines/reference/checkExportsObjectAssignProperty.symbols

@@ -269,18 +269,18 @@ Object.defineProperty(module.exports, "setonlyAccessor", {
  */
 const q = require("./mod1").thing;
 >q : Symbol(q, Decl(index.js, 3, 5))
->require("./mod1").thing : Symbol(thing, Decl(mod1.js, 0, 0))
+>require("./mod1").thing : Symbol(q, Decl(mod1.js, 0, 0))
 >require : Symbol(require)
 >"./mod1" : Symbol("tests/cases/conformance/jsdoc/mod1", Decl(mod1.js, 0, 0))
->thing : Symbol(thing, Decl(mod1.js, 0, 0))
+>thing : Symbol(q, Decl(mod1.js, 0, 0))
 
 /**
  * @type {string}
  */
 const u = require("./mod2").thing;
 >u : Symbol(u, Decl(index.js, 8, 5))
->require("./mod2").thing : Symbol(thing, Decl(mod2.js, 0, 0))
+>require("./mod2").thing : Symbol(u, Decl(mod2.js, 0, 0))
 >require : Symbol(require)
 >"./mod2" : Symbol("tests/cases/conformance/jsdoc/mod2", Decl(mod2.js, 0, 0))
->thing : Symbol(thing, Decl(mod2.js, 0, 0))
+>thing : Symbol(u, Decl(mod2.js, 0, 0))
 

tests/baselines/reference/requireOfJsonFileInJsFile.errors.txt

@@ -1,14 +1,14 @@
-/user.js(2,7): error TS2339: Property 'b' does not exist on type '{ a: number; }'.
+/user.js(2,7): error TS2339: Property 'b' does not exist on type 'typeof "/json"'.
 /user.js(5,7): error TS2741: Property 'b' is missing in type '{ a: number; }' but required in type '{ b: number; }'.
-/user.js(9,7): error TS2339: Property 'b' does not exist on type '{ a: number; }'.
+/user.js(9,7): error TS2339: Property 'b' does not exist on type 'typeof "/json"'.
 /user.js(12,7): error TS2741: Property 'b' is missing in type '{ a: number; }' but required in type '{ b: number; }'.
 
 
 ==== /user.js (4 errors) ====
     const json0 = require("./json.json");
     json0.b; // Error (good)
           ~
-!!! error TS2339: Property 'b' does not exist on type '{ a: number; }'.
+!!! error TS2339: Property 'b' does not exist on type 'typeof "/json"'.
 
     /** @type {{ b: number }} */
     const json1 = require("./json.json"); // No error (bad)
@@ -20,7 +20,7 @@
     const js0 = require("./js.js");
     json0.b; // Error (good)
           ~
-!!! error TS2339: Property 'b' does not exist on type '{ a: number; }'.
+!!! error TS2339: Property 'b' does not exist on type 'typeof "/json"'.
 
     /** @type {{ b: number }} */
     const js1 = require("./js.js"); // Error (good)

tests/baselines/reference/requireOfJsonFileInJsFile.symbols

@@ -2,7 +2,7 @@
 const json0 = require("./json.json");
 >json0 : Symbol(json0, Decl(user.js, 0, 5))
 >require : Symbol(require)
->"./json.json" : Symbol("/json", Decl(json.json, 0, 0))
+>"./json.json" : Symbol(json0, Decl(json.json, 0, 0))
 
 json0.b; // Error (good)
 >json0 : Symbol(json0, Decl(user.js, 0, 5))
@@ -11,7 +11,7 @@ json0.b; // Error (good)
 const json1 = require("./json.json"); // No error (bad)
 >json1 : Symbol(json1, Decl(user.js, 4, 5))
 >require : Symbol(require)
->"./json.json" : Symbol("/json", Decl(json.json, 0, 0))
+>"./json.json" : Symbol(json0, Decl(json.json, 0, 0))
 
 json1.b; // No error (OK since that's the type annotation)
 >json1.b : Symbol(b, Decl(user.js, 3, 12))
@@ -21,7 +21,7 @@ json1.b; // No error (OK since that's the type annotation)
 const js0 = require("./js.js");
 >js0 : Symbol(js0, Decl(user.js, 7, 5))
 >require : Symbol(require)
->"./js.js" : Symbol("/js", Decl(js.js, 0, 0))
+>"./js.js" : Symbol(js0, Decl(js.js, 0, 0))
 
 json0.b; // Error (good)
 >json0 : Symbol(json0, Decl(user.js, 0, 5))
@@ -30,7 +30,7 @@ json0.b; // Error (good)
 const js1 = require("./js.js"); // Error (good)
 >js1 : Symbol(js1, Decl(user.js, 11, 5))
 >require : Symbol(require)
->"./js.js" : Symbol("/js", Decl(js.js, 0, 0))
+>"./js.js" : Symbol(js0, Decl(js.js, 0, 0))
 
 js1.b;
 >js1.b : Symbol(b, Decl(user.js, 10, 12))

tests/baselines/reference/requireOfJsonFileInJsFile.types

@@ -1,13 +1,13 @@
 === /user.js ===
 const json0 = require("./json.json");
->json0 : { a: number; }
+>json0 : typeof json0
 >require("./json.json") : { a: number; }
 >require : any
 >"./json.json" : "./json.json"
 
 json0.b; // Error (good)
 >json0.b : any
->json0 : { a: number; }
+>json0 : typeof json0
 >b : any
 
 /** @type {{ b: number }} */
@@ -30,7 +30,7 @@ const js0 = require("./js.js");
 
 json0.b; // Error (good)
 >json0.b : any
->json0 : { a: number; }
+>json0 : typeof json0
 >b : any
 
 /** @type {{ b: number }} */