test: cleanup test-fs-watch.js

Reversed "actual" and "expected" arguments for assert.strictEqual().

Replaced constructor with regular expression for assert.throws().

PR-URL: nodejs/node#12595
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Bryan English <bryan@bryanenglish.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>

test/sequential/test-fs-watch.js

@@ -35,10 +35,10 @@ assert.doesNotThrow(
     function() {
       const watcher = fs.watch(filepathOne);
       watcher.on('change', function(event, filename) {
-        assert.strictEqual('change', event);
+        assert.strictEqual(event, 'change');
 
         if (expectFilePath) {
-          assert.strictEqual('watch.txt', filename);
+          assert.strictEqual(filename, 'watch.txt');
         }
         watcher.close();
         ++watchSeenOne;
@@ -58,10 +58,10 @@ fs.writeFileSync(filepathTwoAbs, 'howdy');
 assert.doesNotThrow(
     function() {
       const watcher = fs.watch(filepathTwo, function(event, filename) {
-        assert.strictEqual('change', event);
+        assert.strictEqual(event, 'change');
 
         if (expectFilePath) {
-          assert.strictEqual('hasOwnProperty', filename);
+          assert.strictEqual(filename, 'hasOwnProperty');
         }
         watcher.close();
         ++watchSeenTwo;
@@ -83,9 +83,9 @@ assert.doesNotThrow(
         const renameEv = common.isSunOS ? 'change' : 'rename';
         assert.strictEqual(renameEv, event);
         if (expectFilePath) {
-          assert.strictEqual('newfile.txt', filename);
+          assert.strictEqual(filename, 'newfile.txt');
         } else {
-          assert.strictEqual(null, filename);
+          assert.strictEqual(filename, null);
         }
         watcher.close();
         ++watchSeenThree;
@@ -112,13 +112,13 @@ assert.throws(function() {
   oldhandle = w._handle;
   w._handle = { close: w._handle.close };
   w.close();
-}, TypeError);
+}, /^TypeError: Illegal invocation$/);
 oldhandle.close(); // clean up
 
 assert.throws(function() {
   const w = fs.watchFile(__filename, {persistent: false}, function() {});
   oldhandle = w._handle;
   w._handle = { stop: w._handle.stop };
   w.stop();
-}, TypeError);
+}, /^TypeError: Illegal invocation$/);
 oldhandle.stop(); // clean up