feat: supress error 2961 when emitExtension is .ts

Author: Jack-Works

src/compiler/checker.ts

@@ -3051,13 +3051,18 @@ namespace ts {
                 else {
                     const tsExtension = tryExtractTSExtension(moduleReference);
                     if (tsExtension) {
-                        const diag = Diagnostics.An_import_path_cannot_end_with_a_0_extension_Consider_importing_1_instead;
-                        let rightPath = removeExtension(moduleReference, tsExtension);
-                        if (compilerOptions.emitExtension) {
-                            // e.g.: Consider importing '{1}.mjs' instead.
-                            rightPath += compilerOptions.emitExtension;
+                        if (compilerOptions.emitExtension === tsExtension) {
+                            error(errorNode, moduleNotFoundError, moduleReference);
+                        }
+                        else {
+                            const diag = Diagnostics.An_import_path_cannot_end_with_a_0_extension_Consider_importing_1_instead;
+                            let rightPath = removeExtension(moduleReference, tsExtension);
+                            if (compilerOptions.emitExtension) {
+                                // e.g.: Consider importing '{1}.mjs' instead.
+                                rightPath += compilerOptions.emitExtension;
+                            }
+                            error(errorNode, diag, tsExtension, rightPath);
                         }
-                        error(errorNode, diag, tsExtension, rightPath);
                     }
                     else if (!compilerOptions.resolveJsonModule &&
                         fileExtensionIs(moduleReference, Extension.Json) &&
@@ -33664,10 +33669,12 @@ namespace ts {
                         return false;
                     }
                 }
-                else if (compilerOptions.noImplicitExtensionName) {
+                // Skip noImplicitExtensionName check for files in node_modules
+                else if (compilerOptions.noImplicitExtensionName && !getSourceFileOfNode(node).fileName.includes("node_modules")) {
                     const extensionLess = removeFileExtension(moduleName.text, compilerOptions);
                     if (extensionLess === moduleName.text) {
                         error(node, Diagnostics.Import_with_an_implicit_extension_name_is_not_allowed_Try_to_import_from_0_1_instead, extensionLess, compilerOptions.emitExtension || ".js");
+                        return false;
                     }
                 }
             }