Add outer host and port check, and move tests back

Author: dlarocque

packages/rules-unit-testing/src/impl/discovery.ts

@@ -89,22 +89,24 @@ export function getEmulatorHostAndPort(
 ) {
   if (conf && ('host' in conf || 'port' in conf)) {
     const { host, port } = conf as any;
-    if (!host || !port) {
-      throw new Error(
-        `Invalid configuration ${emulator}.host=${host} and ${emulator}.port=${port}. ` +
-          'If either parameter is supplied, both must be defined.'
-      );
+    if (host || port) {
+      if (!host || !port) {
+        throw new Error(
+          `Invalid configuration ${emulator}.host=${host} and ${emulator}.port=${port}. ` +
+            'If either parameter is supplied, both must be defined.'
+        );
+      }
+      if (discovered && !discovered[emulator]) {
+        console.warn(
+          `Warning: config for the ${emulator} emulator is specified, but the Emulator hub ` +
+            'reports it as not running. This may lead to errors such as connection refused.'
+        );
+      }
+      return {
+        host: fixHostname(host, discovered?.hub?.host),
+        port: port
+      };
     }
-    if (discovered && !discovered[emulator]) {
-      console.warn(
-        `Warning: config for the ${emulator} emulator is specified, but the Emulator hub ` +
-          'reports it as not running. This may lead to errors such as connection refused.'
-      );
-    }
-    return {
-      host: fixHostname(host, discovered?.hub?.host),
-      port: port
-    };
   }
   const envVar = EMULATOR_HOST_ENV_VARS[emulator];
   const fallback = discovered?.[emulator] || emulatorFromEnvVar(envVar);

packages/rules-unit-testing/test/impl/discovery.test.ts

@@ -123,6 +123,22 @@ describe('getEmulatorHostAndPort()', () => {
       expect(result?.host).to.equal('::1');
     });
 
+    it('throws if only host is present', async () => {
+      expect(() =>
+        getEmulatorHostAndPort('hub', {
+          host: '[::1]'
+        } as HostAndPort)
+      ).to.throw(/hub.port=undefined/);
+    });
+
+    it('throws if only port is present', async () => {
+      expect(() =>
+        getEmulatorHostAndPort('database', {
+          port: 1234
+        } as HostAndPort)
+      ).to.throw(/Invalid configuration database.host=undefined/);
+    });
+
     it('connect to 127.0.0.1 if host is wildcard 0.0.0.0', async () => {
       const result = getEmulatorHostAndPort('hub', {
         host: '0.0.0.0',
@@ -140,22 +156,6 @@ describe('getEmulatorHostAndPort()', () => {
       expect(result?.host).to.equal('::1');
     });
 
-    it('throws if only host is present', async () => {
-      expect(() =>
-        getEmulatorHostAndPort('hub', {
-          host: '[::1]'
-        } as HostAndPort)
-      ).to.throw(/hub.port=undefined/);
-    });
-
-    it('throws if only port is present', async () => {
-      expect(() =>
-        getEmulatorHostAndPort('database', {
-          port: 1234
-        } as HostAndPort)
-      ).to.throw(/Invalid configuration database.host=undefined/);
-    });
-
     it('uses discovered host/port if both config and env var are unset', async () => {
       const result = getEmulatorHostAndPort('hub', undefined, {
         hub: { host: '::1', port: 3333 }