improve error message TS2307

Author: Philipp Zins

src/compiler/checker.ts

@@ -2211,7 +2211,7 @@ namespace ts {
         }
 
         function resolveExternalModuleName(location: Node, moduleReferenceExpression: Expression): Symbol | undefined {
-            return resolveExternalModuleNameWorker(location, moduleReferenceExpression, Diagnostics.Cannot_find_module_0);
+            return resolveExternalModuleNameWorker(location, moduleReferenceExpression, Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module);
         }
 
         function resolveExternalModuleNameWorker(location: Node, moduleReferenceExpression: Expression, moduleNotFoundError: DiagnosticMessage | undefined, isForAugmentation = false): Symbol | undefined {

src/compiler/diagnosticMessages.json

@@ -1036,7 +1036,7 @@
         "category": "Error",
         "code": 2306
     },
-    "Cannot find module '{0}'.": {
+    "Cannot find module '{0}' or cannot find corresponding type declarations for this module.": {
         "category": "Error",
         "code": 2307
     },

src/testRunner/unittests/tscWatchMode.ts

@@ -230,7 +230,7 @@ namespace ts.tscWatch {
 
     function getDiagnosticModuleNotFoundOfFile(program: Program, file: File, moduleName: string) {
         const quotedModuleName = `"${moduleName}"`;
-        return getDiagnosticOfFileFromProgram(program, file.path, file.content.indexOf(quotedModuleName), quotedModuleName.length, Diagnostics.Cannot_find_module_0, moduleName);
+        return getDiagnosticOfFileFromProgram(program, file.path, file.content.indexOf(quotedModuleName), quotedModuleName.length, Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module, moduleName);
     }
 
     describe("tsc-watch program updates", () => {

src/testRunner/unittests/tsserverProjectSystem.ts

@@ -4679,7 +4679,7 @@ namespace ts.projectSystem {
             host.runQueuedTimeoutCallbacks();
             diags = session.executeCommand(getErrRequest).response as server.protocol.Diagnostic[];
             verifyDiagnostics(diags, [
-                { diagnosticMessage: Diagnostics.Cannot_find_module_0, errorTextArguments: ["./moduleFile"] }
+                { diagnosticMessage: Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module, errorTextArguments: ["./moduleFile"] }
             ]);
             assert.equal(diags.length, 1);
 
@@ -4730,7 +4730,7 @@ namespace ts.projectSystem {
             host.runQueuedTimeoutCallbacks();
             diags = session.executeCommand(getErrRequest).response as server.protocol.Diagnostic[];
             verifyDiagnostics(diags, [
-                { diagnosticMessage: Diagnostics.Cannot_find_module_0, errorTextArguments: ["./moduleFile"] }
+                { diagnosticMessage: Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module, errorTextArguments: ["./moduleFile"] }
             ]);
 
             moduleFile.path = moduleFileOldPath;
@@ -4805,7 +4805,7 @@ namespace ts.projectSystem {
             );
             let diags = session.executeCommand(getErrRequest).response as server.protocol.Diagnostic[];
             verifyDiagnostics(diags, [
-                { diagnosticMessage: Diagnostics.Cannot_find_module_0, errorTextArguments: ["./moduleFile"] }
+                { diagnosticMessage: Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module, errorTextArguments: ["./moduleFile"] }
             ]);
 
             host.reloadFS([file1, moduleFile]);
@@ -4862,7 +4862,7 @@ namespace ts.projectSystem {
             checkErrorMessage(session, "semanticDiag", {
                 file: file1.path,
                 diagnostics: [
-                    createDiagnostic({ line: 1, offset: startOffset }, { line: 1, offset: startOffset + '"pad"'.length }, Diagnostics.Cannot_find_module_0, ["pad"])
+                    createDiagnostic({ line: 1, offset: startOffset }, { line: 1, offset: startOffset + '"pad"'.length }, Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module, ["pad"])
                 ],
             });
             session.clearMessages();
@@ -7039,7 +7039,7 @@ namespace ts.projectSystem {
             let diags = project.getLanguageService().getSemanticDiagnostics(root.path);
             assert.equal(diags.length, 1);
             const diag = diags[0];
-            assert.equal(diag.code, Diagnostics.Cannot_find_module_0.code);
+            assert.equal(diag.code, Diagnostics.Cannot_find_module_0_or_cannot_find_corresponding_type_declarations_for_this_module.code);
             assert.equal(flattenDiagnosticMessageText(diag.messageText, "\n"), "Cannot find module 'bar'.");
             callsTrackingHost.verifyCalledOn(CalledMapsWithSingleArg.fileExists, imported.path);