select tests by process env

test/node.js

@@ -1,5 +1,35 @@
 'use strict'
 
-require('./core-tests')
-require('./http-api-tests')
-require('./cli-tests')
+let testCore = true
+let testHTTP = true
+let testCLI = true
+
+if (process.env.TEST) {
+  switch (process.env.TEST) {
+    case 'core': {
+      testHTTP = false
+      testCLI = false
+    } break
+    case 'http': {
+      testCore = false
+      testCLI = false
+    } break
+    case 'cli': {
+      testCore = false
+      testCLI = false
+    } break
+    default: break
+  }
+}
+
+if (testCore) {
+  require('./core-tests')
+}
+
+if (testHTTP) {
+  require('./http-api-tests')
+}
+
+if (testCLI) {
+  require('./cli-tests')
+}