Clarified file-not-found error for reference paths without extensions (#35956)

* Clarified file-not-found error for reference paths without extensions

* Updated error message to include extensions

* update baselines missed in merge

Co-authored-by: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>

Author: JoshuaKGoldberg

src/compiler/diagnosticMessages.json

@@ -4324,6 +4324,10 @@
         "category": "Error",
         "code": 6230
     },
+    "Could not resolve the path '{0}' with the extensions: {1}.": {
+        "category": "Error",
+        "code": 6231
+    },
 
     "Projects to reference": {
         "category": "Message",

src/compiler/program.ts

@@ -1925,7 +1925,7 @@ namespace ts {
                                 diagnostics.push(createDiagnosticForNodeArray(nodes, Diagnostics.Type_parameter_declarations_can_only_be_used_in_TypeScript_files));
                                 return "skip";
                             }
-                            // falls through
+                        // falls through
 
                         case SyntaxKind.VariableStatement:
                             // Check modifiers
@@ -2270,7 +2270,7 @@ namespace ts {
                 }
 
                 const sourceFileWithAddedExtension = forEach(supportedExtensions, extension => getSourceFile(fileName + extension));
-                if (fail && !sourceFileWithAddedExtension) fail(Diagnostics.File_0_not_found, fileName + Extension.Ts);
+                if (fail && !sourceFileWithAddedExtension) fail(Diagnostics.Could_not_resolve_the_path_0_with_the_extensions_Colon_1, fileName, "'" + supportedExtensions.join("', '") + "'");
                 return sourceFileWithAddedExtension;
             }
         }

tests/baselines/reference/declarationEmitInvalidReferenceAllowJs.errors.txt

@@ -0,0 +1,9 @@
+tests/cases/compiler/declarationEmitInvalidReferenceAllowJs.ts(1,22): error TS6231: Could not resolve the path 'tests/cases/compiler/invalid' with the extensions: '.ts', '.tsx', '.d.ts', '.js', '.jsx'.
+
+
+==== tests/cases/compiler/declarationEmitInvalidReferenceAllowJs.ts (1 errors) ====
+    /// <reference path="invalid" />
+                         ~~~~~~~
+!!! error TS6231: Could not resolve the path 'tests/cases/compiler/invalid' with the extensions: '.ts', '.tsx', '.d.ts', '.js', '.jsx'.
+    var x = 0; 
+    

tests/baselines/reference/declarationEmitInvalidReferenceAllowJs.js

@@ -0,0 +1,12 @@
+//// [declarationEmitInvalidReferenceAllowJs.ts]
+/// <reference path="invalid" />
+var x = 0; 
+
+
+//// [declarationEmitInvalidReferenceAllowJs.js]
+/// <reference path="invalid" />
+var x = 0;
+
+
+//// [declarationEmitInvalidReferenceAllowJs.d.ts]
+declare var x: number;

tests/baselines/reference/declarationEmitInvalidReferenceAllowJs.symbols

@@ -0,0 +1,5 @@
+=== tests/cases/compiler/declarationEmitInvalidReferenceAllowJs.ts ===
+/// <reference path="invalid" />
+var x = 0; 
+>x : Symbol(x, Decl(declarationEmitInvalidReferenceAllowJs.ts, 1, 3))
+

tests/baselines/reference/declarationEmitInvalidReferenceAllowJs.types

@@ -0,0 +1,6 @@
+=== tests/cases/compiler/declarationEmitInvalidReferenceAllowJs.ts ===
+/// <reference path="invalid" />
+var x = 0; 
+>x : number
+>0 : 0
+

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

@@ -1,6 +1,8 @@
 error TS6053: File 'a.ts' not found.
 error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+error TS6231: Could not resolve the path 'a' with the extensions: '.ts', '.tsx', '.d.ts'.
 
 
 !!! error TS6053: File 'a.ts' not found.
-!!! error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+!!! error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+!!! error TS6231: Could not resolve the path 'a' with the extensions: '.ts', '.tsx', '.d.ts'.

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

@@ -1,6 +1,8 @@
 error TS6053: File 'a.ts' not found.
 error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+error TS6231: Could not resolve the path 'a' with the extensions: '.ts', '.tsx', '.d.ts'.
 
 
 !!! error TS6053: File 'a.ts' not found.
-!!! error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+!!! error TS6054: File 'a.t' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
+!!! error TS6231: Could not resolve the path 'a' with the extensions: '.ts', '.tsx', '.d.ts'.

tests/cases/compiler/declarationEmitInvalidReferenceAllowJs.ts

@@ -0,0 +1,4 @@
+// @allowJs: true
+// @declaration: true
+/// <reference path="invalid" />
+var x = 0;