fix corner case in reduce_vars

[alexlamsl]

@kzc another one from harmony − current patch for test/compress.js

--- a/test/compress.js
+++ b/test/compress.js
@@ -14 +14 @@ var batch = 50;
-var dir = path.resolve(path.dirname(module.filename), "compress");
+var dir = path.resolve(path.dirname(module.filename), "../../UglifyJS-harmony/test/compress");
@@ -141,0 +142 @@ function parse_test(file) {
+                    "reminify",
@@ -193,0 +195,4 @@ function reminify(orig_options, input_code, input_formatted, stdout) {
+        if ("keep_fnames" in orig_options) {
+            options.keep_fnames = orig_options.keep_fnames;
+            delete options.rename;
+        }
@@ -255,0 +261,11 @@ function test_case(test) {
+    [ "ecma" ].forEach(function(name) {
+        if (name in output_options) delete output_options[name];
+    });
+    if ("bracketize" in output_options) {
+        output_options.braces = output_options.bracketize;
+        delete output_options.bracketize;
+    }
+    if ("safari10" in output_options) {
+        output_options.webkit = output_options.safari10;
+        delete output_options.safari10;
+    }
@@ -308,0 +325,13 @@ function test_case(test) {
+    [
+        "computed_props",
+        "ecma",
+        "unsafe_arrows",
+        "unsafe_methods",
+        "warnings",
+    ].forEach(function(name) {
+        if (name in test.options) delete test.options[name];
+    });
+    if ("keep_classnames" in test.options) {
+        test.options.keep_fnames = test.options.keep_classnames;
+        delete test.options.keep_classnames;
+    }
@@ -319 +348 @@ function test_case(test) {
-    if (expect != output_code) {
+    if (0 && expect != output_code) {
@@ -359 +388 @@ function test_case(test) {
-    if (test.expect_warnings) {
+    if (0 && test.expect_warnings) {
@@ -390 +419 @@ function test_case(test) {
-        if (test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {
+        if (1 || test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {

[kzc]

Is that the last of the issues unearthed by uglify-es? So it only found two problems?

In my compress test runner if process.env.IGNORE_EXPECT is set, it skips the tests without expect_stdout and it ignores expect: and expect_exact: altogether. That way it can run tests from uglify-js, uglify-es and terser.

I did notice that you added class support to keep_fnames. That's good. You get some extra granularity with keep_classnames, but it's not a big deal.

[alexlamsl]

Is that the last of the issues unearthed by uglify-es? So it only found two problems?

Oh #4790 onwards are all results of the scan thus far. And I think there are a few more further down − I'm only up to reduce_vars.js

[alexlamsl]

Oh and I took out tests in export.js and harmony.js that parser would throw (after confirming SyntaxErrors from Node.js)