goGenerateTests: resolve config file path

Fixes #2342

Change-Id: If40a6941537ad54ffd58154c28eec610057fb8dc
GitHub-Last-Rev: b9342aa
GitHub-Pull-Request: #2344
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/417675
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
Reviewed-by: Jamal Carvalho <[email protected]>
TryBot-Result: kokoro <[email protected]>
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>

Author: ras0q

src/goGenerateTests.ts

@@ -16,7 +16,7 @@ import { toolExecutionEnvironment } from './goEnv';
 import { promptForMissingTool } from './goInstallTools';
 import { GoDocumentSymbolProvider } from './goDocumentSymbols';
 import { outputChannel } from './goStatus';
-import { getBinPath } from './util';
+import { getBinPath, resolvePath } from './util';
 import { CommandFactory } from './commands';
 import { GoExtensionContext } from './context';
 
@@ -178,6 +178,12 @@ function generateTests(
 				i++;
 				continue;
 			}
+			if (i + 1 < goGenerateTestsFlags.length && (flag === '-template_dir' || flag === '-template_params_file')) {
+				const configFilePath = resolvePath(goGenerateTestsFlags[i + 1]);
+				args.push(flag, configFilePath);
+				i++;
+				continue;
+			}
 			args.push(flag);
 		}