make number of test parallelism configurable

Signed-off-by: Jannik Glückert <jannik.glueckert@gmail.com>

Author: Jannik2099

package.json

@@ -158,6 +158,12 @@
           "default": {},
           "description": "Specify the list of additional environment variables used for running tests."
         },
+        "mesonbuild.testJobs": {
+          "type": "integer",
+          "default": -1,
+          "minimum": -1,
+          "description": "Specify the maximum number of tests executed in parallel. -1 for number of CPUs, 0 for unlimited."
+        },
         "mesonbuild.benchmarkOptions": {
           "type": "array",
           "default": [

src/tests.ts

@@ -109,7 +109,17 @@ export async function testRunHandler(
   }
 
   const running_tests: Promise<void>[] = [];
-  const max_running = os.cpus().length;
+  const max_running: number = (() => {
+    const jobs_config = extensionConfiguration("testJobs");
+    switch (jobs_config) {
+      case -1:
+        return os.cpus().length;
+      case 0:
+        return Number.MAX_SAFE_INTEGER;
+      default:
+        return jobs_config;
+    }
+  })();
 
   for (const test of parallelTests) {
     const running_test = dispatchTest(test).finally(() => {

src/types.ts

@@ -72,6 +72,7 @@ export interface ExtensionConfiguration {
   setupOptions: string[];
   testOptions: string[];
   testEnvironment: { [key: string]: string };
+  testJobs: number;
   benchmarkOptions: string[];
   buildFolder: string;
   mesonPath: string;