Better errors for types with same name

src/compiler/checker.ts

@@ -3508,7 +3508,15 @@ module ts {
                 }
                 if (reportErrors) {
                     headMessage = headMessage || Diagnostics.Type_0_is_not_assignable_to_type_1;
-                    reportError(headMessage, typeToString(source), typeToString(target));
+                    var sourceType = typeToString(source);
+                    var targetType = typeToString(target);
+                    if (sourceType !== targetType) {
+                        reportError(headMessage, sourceType, targetType);
+                    } else {
+                        // If the types are incompatible but have the same name, use the qualified names to give
+                        // a more insightful error message
+                        reportError(headMessage, getFullyQualifiedName(source.symbol), getFullyQualifiedName(target.symbol));
+                    }
                 }
                 return Ternary.False;
             }

tests/baselines/reference/clodulesDerivedClasses.errors.txt

@@ -1,6 +1,6 @@
 tests/cases/compiler/clodulesDerivedClasses.ts(9,7): error TS2417: Class static side 'typeof Path' incorrectly extends base class static side 'typeof Shape'.
   Types of property 'Utils' are incompatible.
-    Type 'typeof Utils' is not assignable to type 'typeof Utils'.
+    Type 'Path.Utils' is not assignable to type 'Shape.Utils'.
       Property 'convert' is missing in type 'typeof Utils'.
 
 
@@ -17,7 +17,7 @@ tests/cases/compiler/clodulesDerivedClasses.ts(9,7): error TS2417: Class static
           ~~~~
 !!! error TS2417: Class static side 'typeof Path' incorrectly extends base class static side 'typeof Shape'.
 !!! error TS2417:   Types of property 'Utils' are incompatible.
-!!! error TS2417:     Type 'typeof Utils' is not assignable to type 'typeof Utils'.
+!!! error TS2417:     Type 'Path.Utils' is not assignable to type 'Shape.Utils'.
 !!! error TS2417:       Property 'convert' is missing in type 'typeof Utils'.
         name: string;
 

tests/baselines/reference/differentTypesWithSameName.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/compiler/differentTypesWithSameName.ts(16,15): error TS2345: Argument of type 'variable' is not assignable to parameter of type 'm.variable'.
+
+
+==== tests/cases/compiler/differentTypesWithSameName.ts (1 errors) ====
+    module m {
+      export class variable{
+        s: string;
+      }
+      export function doSomething(v: m.variable) {
+
+      }
+    }
+
+    class variable {
+     t: number;
+    }
+
+
+    var v: variable = new variable();
+    m.doSomething(v);
+                  ~
+!!! error TS2345: Argument of type 'variable' is not assignable to parameter of type 'm.variable'.

tests/baselines/reference/differentTypesWithSameName.js

@@ -0,0 +1,38 @@
+//// [differentTypesWithSameName.ts]
+module m {
+  export class variable{
+    s: string;
+  }
+  export function doSomething(v: m.variable) {
+
+  }
+}
+
+class variable {
+ t: number;
+}
+
+
+var v: variable = new variable();
+m.doSomething(v);
+
+//// [differentTypesWithSameName.js]
+var m;
+(function (m) {
+    var variable = (function () {
+        function variable() {
+        }
+        return variable;
+    })();
+    m.variable = variable;
+    function doSomething(v) {
+    }
+    m.doSomething = doSomething;
+})(m || (m = {}));
+var variable = (function () {
+    function variable() {
+    }
+    return variable;
+})();
+var v = new variable();
+m.doSomething(v);

tests/baselines/reference/everyTypeWithAnnotationAndInvalidInitializer.errors.txt

@@ -25,10 +25,10 @@ tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAnd
   Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAndInvalidInitializer.ts(50,5): error TS2322: Type 'typeof N' is not assignable to type 'typeof M'.
   Types of property 'A' are incompatible.
-    Type 'typeof A' is not assignable to type 'typeof A'.
-      Type 'A' is not assignable to type 'A'.
+    Type 'N.A' is not assignable to type 'M.A'.
+      Type 'N.A' is not assignable to type 'M.A'.
         Property 'name' is missing in type 'A'.
-tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAndInvalidInitializer.ts(51,5): error TS2322: Type 'A' is not assignable to type 'A'.
+tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAndInvalidInitializer.ts(51,5): error TS2322: Type 'N.A' is not assignable to type 'M.A'.
 tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAndInvalidInitializer.ts(52,5): error TS2322: Type '(x: number) => boolean' is not assignable to type '(x: number) => string'.
   Type 'boolean' is not assignable to type 'string'.
 
@@ -124,12 +124,12 @@ tests/cases/conformance/statements/VariableStatements/everyTypeWithAnnotationAnd
         ~~~~~~~
 !!! error TS2322: Type 'typeof N' is not assignable to type 'typeof M'.
 !!! error TS2322:   Types of property 'A' are incompatible.
-!!! error TS2322:     Type 'typeof A' is not assignable to type 'typeof A'.
-!!! error TS2322:       Type 'A' is not assignable to type 'A'.
+!!! error TS2322:     Type 'N.A' is not assignable to type 'M.A'.
+!!! error TS2322:       Type 'N.A' is not assignable to type 'M.A'.
 !!! error TS2322:         Property 'name' is missing in type 'A'.
     var aClassInModule: M.A = new N.A();
         ~~~~~~~~~~~~~~
-!!! error TS2322: Type 'A' is not assignable to type 'A'.
+!!! error TS2322: Type 'N.A' is not assignable to type 'M.A'.
     var aFunctionInModule: typeof M.F2 = F2;
         ~~~~~~~~~~~~~~~~~
 !!! error TS2322: Type '(x: number) => boolean' is not assignable to type '(x: number) => string'.

tests/baselines/reference/qualify.errors.txt

@@ -10,7 +10,7 @@ tests/cases/compiler/qualify.ts(47,13): error TS2322: Type 'I4' is not assignabl
 tests/cases/compiler/qualify.ts(48,13): error TS2322: Type 'I4' is not assignable to type '(k: I3) => void'.
 tests/cases/compiler/qualify.ts(49,13): error TS2322: Type 'I4' is not assignable to type '{ k: I3; }'.
   Property 'k' is missing in type 'I4'.
-tests/cases/compiler/qualify.ts(58,5): error TS2322: Type 'I' is not assignable to type 'I'.
+tests/cases/compiler/qualify.ts(58,5): error TS2322: Type 'I' is not assignable to type 'T.I'.
   Property 'p' is missing in type 'I'.
 
 
@@ -93,7 +93,7 @@ tests/cases/compiler/qualify.ts(58,5): error TS2322: Type 'I' is not assignable
     var y:I;
     var x:T.I=y;
         ~
-!!! error TS2322: Type 'I' is not assignable to type 'I'.
+!!! error TS2322: Type 'I' is not assignable to type 'T.I'.
 !!! error TS2322:   Property 'p' is missing in type 'I'.
 
 

tests/cases/compiler/differentTypesWithSameName.ts

@@ -0,0 +1,16 @@
+module m {
+  export class variable{
+    s: string;
+  }
+  export function doSomething(v: m.variable) {
+
+  }
+}
+
+class variable {
+ t: number;
+}
+
+
+var v: variable = new variable();
+m.doSomething(v);