Merge branch 'master' into resolveJsonModuleError

src/compiler/checker.ts

@@ -20047,7 +20047,8 @@ namespace ts {
             if (produceDiagnostics && targetType !== errorType) {
                 const widenedType = getWidenedType(exprType);
                 if (!isTypeComparableTo(targetType, widenedType)) {
-                    checkTypeComparableTo(exprType, targetType, errNode, Diagnostics.Type_0_cannot_be_converted_to_type_1);
+                    checkTypeComparableTo(exprType, targetType, errNode,
+                        Diagnostics.Conversion_of_type_0_to_type_1_may_be_a_mistake_because_neither_type_sufficiently_overlaps_with_the_other_If_this_was_intentional_convert_the_expression_to_unknown_first);
                 }
             }
             return targetType;
@@ -21521,7 +21522,7 @@ namespace ts {
             // in tagged templates.
             forEach(node.templateSpans, templateSpan => {
                 if (maybeTypeOfKind(checkExpression(templateSpan.expression), TypeFlags.ESSymbolLike)) {
-                    error(templateSpan.expression, Diagnostics.Type_0_cannot_be_converted_to_type_1, typeToString(esSymbolType), typeToString(stringType));
+                    error(templateSpan.expression, Diagnostics.Implicit_conversion_of_a_symbol_to_a_string_will_fail_at_runtime_Consider_wrapping_this_expression_in_String);
                 }
             });
 

src/compiler/diagnosticMessages.json

@@ -1196,7 +1196,7 @@
         "category": "Error",
         "code": 2351
     },
-    "Type '{0}' cannot be converted to type '{1}'.": {
+    "Conversion of type '{0}' to type '{1}' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.": {
         "category": "Error",
         "code": 2352
     },
@@ -2421,10 +2421,14 @@
         "category": "Error",
         "code": 2730
     },
-    "Cannot find module '{0}'. Consider using '--resolveJsonModule' to import module with '.json' extension": {
+    "Implicit conversion of a 'symbol' to a 'string' will fail at runtime. Consider wrapping this expression in 'String(...)'.": {
         "category": "Error",
         "code": 2731
     },
+    "Cannot find module '{0}'. Consider using '--resolveJsonModule' to import module with '.json' extension": {
+        "category": "Error",
+        "code": 2732
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",