Initial work on overload resolution with tagged templates.

Currently type argument inference breaks hard when the first parameter of a tag has a generic type.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -122,6 +122,17 @@ module ts {
         return result;
     }
 
+    /**
+     * Returns the last element of an array if non-empty, undefined otherwise.
+     */
+    export function lastOrUndefined<T>(array: T[]): T {
+        if (array.length === 0) {
+            return undefined;
+        }
+
+        return array[array.length - 1];
+    }
+
     export function binarySearch(array: number[], value: number): number {
         var low = 0;
         var high = array.length - 1;

src/compiler/core.ts

@@ -484,6 +484,10 @@ declare var Number: {
     POSITIVE_INFINITY: number;
 }
 
+interface TemplateStringsArray extends Array<string> {
+    raw: string[];
+}
+
 interface Math {
     /** The mathematical constant e. This is Euler's number, the base of natural logarithms. */
     E: number;

src/lib/core.d.ts

@@ -1,10 +1,12 @@
 error TS2318: Cannot find global type 'Boolean'.
 error TS2318: Cannot find global type 'IArguments'.
+error TS2318: Cannot find global type 'TemplateStringsArray'.
 tests/cases/compiler/noDefaultLib.ts(4,11): error TS2317: Global type 'Array' must have 1 type parameter(s).
 
 
 !!! error TS2318: Cannot find global type 'Boolean'.
 !!! error TS2318: Cannot find global type 'IArguments'.
+!!! error TS2318: Cannot find global type 'TemplateStringsArray'.
 ==== tests/cases/compiler/noDefaultLib.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
     var x;

tests/baselines/reference/noDefaultLib.errors.txt

@@ -6,6 +6,7 @@ error TS2318: Cannot find global type 'Number'.
 error TS2318: Cannot find global type 'Object'.
 error TS2318: Cannot find global type 'RegExp'.
 error TS2318: Cannot find global type 'String'.
+error TS2318: Cannot find global type 'TemplateStringsArray'.
 
 
 !!! error TS2318: Cannot find global type 'Array'.
@@ -16,6 +17,7 @@ error TS2318: Cannot find global type 'String'.
 !!! error TS2318: Cannot find global type 'Object'.
 !!! error TS2318: Cannot find global type 'RegExp'.
 !!! error TS2318: Cannot find global type 'String'.
+!!! error TS2318: Cannot find global type 'TemplateStringsArray'.
 ==== tests/cases/conformance/parser/ecmascript5/RegressionTests/parser509698.ts (0 errors) ====
     /// <style requireSemi="on" />
     /// <reference no-default-lib="true"/>

tests/baselines/reference/parser509698.errors.txt

@@ -6,6 +6,7 @@ error TS2318: Cannot find global type 'Number'.
 error TS2318: Cannot find global type 'Object'.
 error TS2318: Cannot find global type 'RegExp'.
 error TS2318: Cannot find global type 'String'.
+error TS2318: Cannot find global type 'TemplateStringsArray'.
 test.ts(3,8): error TS2304: Cannot find name 'Array'.
 
 
@@ -17,6 +18,7 @@ test.ts(3,8): error TS2304: Cannot find name 'Array'.
 !!! error TS2318: Cannot find global type 'Object'.
 !!! error TS2318: Cannot find global type 'RegExp'.
 !!! error TS2318: Cannot find global type 'String'.
+!!! error TS2318: Cannot find global type 'TemplateStringsArray'.
 ==== test.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
 

tests/baselines/reference/project/noDefaultLib/amd/noDefaultLib.errors.txt

@@ -6,6 +6,7 @@ error TS2318: Cannot find global type 'Number'.
 error TS2318: Cannot find global type 'Object'.
 error TS2318: Cannot find global type 'RegExp'.
 error TS2318: Cannot find global type 'String'.
+error TS2318: Cannot find global type 'TemplateStringsArray'.
 test.ts(3,8): error TS2304: Cannot find name 'Array'.
 
 
@@ -17,6 +18,7 @@ test.ts(3,8): error TS2304: Cannot find name 'Array'.
 !!! error TS2318: Cannot find global type 'Object'.
 !!! error TS2318: Cannot find global type 'RegExp'.
 !!! error TS2318: Cannot find global type 'String'.
+!!! error TS2318: Cannot find global type 'TemplateStringsArray'.
 ==== test.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
 

tests/baselines/reference/project/noDefaultLib/node/noDefaultLib.errors.txt

@@ -8,9 +8,17 @@ tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTyped
 tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(24,1): error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
 tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(26,1): error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
 tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(26,1): error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(28,1): error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(28,1): error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(14,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(18,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(22,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(24,25): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(26,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts(28,57): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
 
-==== tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts (10 errors) ====
+==== tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTags.ts (18 errors) ====
     interface I {
         (stringParts: string[], ...rest: boolean[]): I;
         g: I;
@@ -29,6 +37,8 @@ tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTyped
     f `abc${1}def${2}ghi`;
     ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
     f `abc`.member
     ~~~~~~~
@@ -37,6 +47,8 @@ tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTyped
     f `abc${1}def${2}ghi`.member;
     ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
     f `abc`["member"];
     ~~~~~~~
@@ -45,18 +57,32 @@ tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTyped
     f `abc${1}def${2}ghi`["member"];
     ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
     f `abc`[0].member `abc${1}def${2}ghi`;
     ~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+                            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
     f `abc${1}def${2}ghi`["member"].member `abc${1}def${2}ghi`;
     ~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc${ true }def${ true }ghi`["member"].member `abc${ 1 }def${ 2 }ghi`;
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1160: Tagged templates are only available when targeting ECMAScript 6 and higher.
+                                                            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
 
     f.thisIsNotATag(`abc`);
 

tests/baselines/reference/taggedTemplateStringsWithIncompatibleTypedTags.errors.txt

@@ -0,0 +1,53 @@
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(14,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(18,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(22,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(24,25): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(26,9): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts(28,57): error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+
+
+==== tests/cases/conformance/es6/templates/taggedTemplateStringsWithIncompatibleTypedTagsES6.ts (6 errors) ====
+    interface I {
+        (stringParts: string[], ...rest: boolean[]): I;
+        g: I;
+        h: I;
+        member: I;
+        thisIsNotATag(x: string): void
+        [x: number]: I;
+    }
+    
+    var f: I;
+    
+    f `abc`
+    
+    f `abc${1}def${2}ghi`;
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc`.member
+    
+    f `abc${1}def${2}ghi`.member;
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc`["member"];
+    
+    f `abc${1}def${2}ghi`["member"];
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc`[0].member `abc${1}def${2}ghi`;
+                            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc${1}def${2}ghi`["member"].member `abc${1}def${2}ghi`;
+            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f `abc${ true }def${ true }ghi`["member"].member `abc${ 1 }def${ 2 }ghi`;
+                                                            ~
+!!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'boolean'.
+    
+    f.thisIsNotATag(`abc`);
+    
+    f.thisIsNotATag(`abc${1}def${2}ghi`);

tests/baselines/reference/taggedTemplateStringsWithIncompatibleTypedTagsES6.errors.txt

@@ -26,10 +26,11 @@ f `abc`[0].member `abc${1}def${2}ghi`;
 
 f `abc${1}def${2}ghi`["member"].member `abc${1}def${2}ghi`;
 
+f `abc${ true }def${ true }ghi`["member"].member `abc${ 1 }def${ 2 }ghi`;
+
 f.thisIsNotATag(`abc`);
 
-f.thisIsNotATag(`abc${1}def${2}ghi`);
-
+f.thisIsNotATag(`abc${1}def${2}ghi`);
 
 //// [taggedTemplateStringsWithIncompatibleTypedTagsES6.js]
 var f;
@@ -41,5 +42,6 @@ f `abc`["member"];
 f `abc${1}def${2}ghi`["member"];
 f `abc`[0].member `abc${1}def${2}ghi`;
 f `abc${1}def${2}ghi`["member"].member `abc${1}def${2}ghi`;
+f `abc${true}def${true}ghi`["member"].member `abc${1}def${2}ghi`;
 f.thisIsNotATag(`abc`);
 f.thisIsNotATag(`abc${1}def${2}ghi`);

tests/baselines/reference/taggedTemplateStringsWithIncompatibleTypedTagsES6.js

@@ -3,7 +3,7 @@ tests/cases/conformance/es6/templates/taggedTemplateStringsWithManyCallAndMember
 
 ==== tests/cases/conformance/es6/templates/taggedTemplateStringsWithManyCallAndMemberExpressions.ts (1 errors) ====
     interface I {
-        (strs: string[], subs: number[]): I;
+        (strs: string[], ...subs: number[]): I;
         member: {
             new (s: string): {
                 new (n: number): {

tests/baselines/reference/taggedTemplateStringsWithIncompatibleTypedTagsES6.types

@@ -1,6 +1,6 @@
 //// [taggedTemplateStringsWithManyCallAndMemberExpressionsES6.ts]
 interface I {
-    (strs: string[], subs: number[]): I;
+    (strs: string[], ...subs: number[]): I;
     member: {
         new (s: string): {
             new (n: number): {

tests/baselines/reference/taggedTemplateStringsWithManyCallAndMemberExpressions.errors.txt

@@ -2,7 +2,7 @@
 interface I {
 >I : I
 
-    (strs: string[], subs: number[]): I;
+    (strs: string[], ...subs: number[]): I;
 >strs : string[]
 >subs : number[]
 >I : I
@@ -28,11 +28,11 @@ var f: I;
 var x = new new new f `abc${ 0 }def`.member("hello")(42) === true;
 >x : boolean
 >new new new f `abc${ 0 }def`.member("hello")(42) === true : boolean
->new new new f `abc${ 0 }def`.member("hello")(42) : any
->new new f `abc${ 0 }def`.member("hello")(42) : any
->new f `abc${ 0 }def`.member("hello") : any
->f `abc${ 0 }def`.member : any
+>new new new f `abc${ 0 }def`.member("hello")(42) : boolean
+>new new f `abc${ 0 }def`.member("hello")(42) : new () => boolean
+>new f `abc${ 0 }def`.member("hello") : new (n: number) => new () => boolean
+>f `abc${ 0 }def`.member : new (s: string) => new (n: number) => new () => boolean
 >f : I
->member : any
+>member : new (s: string) => new (n: number) => new () => boolean