microsoft#40763 Fixed: Bad error message when forgetting a comma in an array of templ… (microsoft#40907)

* microsoft#40763 Bad error message when forgetting a comma in an array of template strings

* Code review fixes

Author: richa008

src/compiler/checker.ts

@@ -27873,6 +27873,12 @@ namespace ts {
             }
 
             if (!callSignatures.length) {
+                if (isArrayLiteralExpression(node.parent)) {
+                    const diagnostic = createDiagnosticForNode(node.tag, Diagnostics.It_is_likely_that_you_are_missing_a_comma_to_separate_these_two_template_expressions_They_form_a_tagged_template_expression_which_cannot_be_invoked);
+                    diagnostics.add(diagnostic);
+                    return resolveErrorCall(node);
+                }
+
                 invocationError(node.tag, apparentType, SignatureKind.Call);
                 return resolveErrorCall(node);
             }

src/compiler/diagnosticMessages.json

@@ -3048,6 +3048,10 @@
         "category": "Error",
         "code": 2795
     },
+    "It is likely that you are missing a comma to separate these two template expressions. They form a tagged template expression which cannot be invoked.": {
+        "category": "Error",
+        "code": 2796
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

tests/baselines/reference/missingCommaInTemplateStringsArray.errors.txt

@@ -0,0 +1,10 @@
+tests/cases/compiler/missingCommaInTemplateStringsArray.ts(2,5): error TS2796: It is likely that you are missing a comma to separate these two template expressions. They form a tagged template expression which cannot be invoked.
+
+
+==== tests/cases/compiler/missingCommaInTemplateStringsArray.ts (1 errors) ====
+    var array = [
+        `template string 1`
+        ~~~~~~~~~~~~~~~~~~~
+!!! error TS2796: It is likely that you are missing a comma to separate these two template expressions. They form a tagged template expression which cannot be invoked.
+        `template string 2`
+      ];

tests/baselines/reference/missingCommaInTemplateStringsArray.js

@@ -0,0 +1,14 @@
+//// [missingCommaInTemplateStringsArray.ts]
+var array = [
+    `template string 1`
+    `template string 2`
+  ];
+
+//// [missingCommaInTemplateStringsArray.js]
+var __makeTemplateObject = (this && this.__makeTemplateObject) || function (cooked, raw) {
+    if (Object.defineProperty) { Object.defineProperty(cooked, "raw", { value: raw }); } else { cooked.raw = raw; }
+    return cooked;
+};
+var array = [
+    "template string 1"(__makeTemplateObject(["template string 2"], ["template string 2"]))
+];

tests/baselines/reference/missingCommaInTemplateStringsArray.symbols

@@ -0,0 +1,7 @@
+=== tests/cases/compiler/missingCommaInTemplateStringsArray.ts ===
+var array = [
+>array : Symbol(array, Decl(missingCommaInTemplateStringsArray.ts, 0, 3))
+
+    `template string 1`
+    `template string 2`
+  ];

tests/baselines/reference/missingCommaInTemplateStringsArray.types

@@ -0,0 +1,13 @@
+=== tests/cases/compiler/missingCommaInTemplateStringsArray.ts ===
+var array = [
+>array : any[]
+>[    `template string 1`    `template string 2`  ] : any[]
+
+    `template string 1`
+>`template string 1`    `template string 2` : any
+>`template string 1` : "template string 1"
+
+    `template string 2`
+>`template string 2` : "template string 2"
+
+  ];

tests/cases/compiler/missingCommaInTemplateStringsArray.ts

@@ -0,0 +1,4 @@
+var array = [
+    `template string 1`
+    `template string 2`
+  ];