fix & enhance collapse_vars (#4447)

fixes #4446

test/compress/collapse_vars.js

@@ -4273,8 +4273,8 @@ issue_2436_14: {
         var b = {};
         (function() {
             a && function(c, d) {
-                console.log(c, d);
-            }(b, a);
+                console.log(b, d);
+            }(0, a);
         })();
     }
     expect_stdout: true

test/compress/default-values.js

@@ -974,3 +974,41 @@ issue_4444: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_4446_1: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        a = 42;
+        [ b = 42 ] = [ "PASS" ];
+        c = 42;
+        console.log(b, a);
+    }
+    expect: {
+        [ b = 42 ] = [ "PASS" ];
+        c = a = 42;
+        console.log(b, a);
+    }
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}
+
+issue_4446_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        a = 42;
+        var [ b = 42 ] = [ "PASS" ];
+        c = 42;
+        console.log(b, a);
+    }
+    expect: {
+        var [ b = 42 ] = [ "PASS" ];
+        c = a = 42;
+        console.log(b, a);
+    }
+    expect_stdout: "PASS 42"
+    node_version: ">=6"
+}

test/compress/destructured.js

@@ -2146,3 +2146,21 @@ issue_4436_undefined: {
     expect_stdout: true
     node_version: ">=6"
 }
+
+issue_4446: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        a = "PASS";
+        var a = [ a[0] ] = [ a ];
+        console.log(a[0]);
+    }
+    expect: {
+        a = "PASS";
+        var a = [ a[0] ] = [ a ];
+        console.log(a[0]);
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}

test/reduce.js

@@ -153,6 +153,20 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                     node.left,
                     node.right,
                 ][ permute & 1 ];
+                if (expr instanceof U.AST_Destructured) expr = expr.transform(new U.TreeTransformer(function(node, descend) {
+                    if (node instanceof U.AST_DefaultValue) return new U.AST_Assign({
+                        operator: "=",
+                        left: node.name.transform(this),
+                        right: node.value,
+                        start: {},
+                    });
+                    if (node instanceof U.AST_DestructuredKeyVal) return new U.AST_ObjectKeyVal(node);
+                    if (node instanceof U.AST_Destructured) {
+                        node = new (node instanceof U.AST_DestructuredArray ? U.AST_Array : U.AST_Object)(node);
+                        descend(node, this);
+                    }
+                    return node;
+                }));
                 CHANGED = true;
                 return permute < 2 ? expr : wrap_with_console_log(expr);
             }

test/ufuzz/index.js

@@ -1680,18 +1680,20 @@ function log(options) {
         }
     }
     errorln("//-------------------------------------------------------------");
-    var reduce_options = JSON.parse(options);
-    reduce_options.validate = true;
-    var reduced = reduce_test(original_code, reduce_options, {
-        verbose: false,
-    }).code;
-    if (reduced) {
-        errorln();
-        errorln("// reduced test case (output will differ)");
-        errorln();
-        errorln(reduced);
-        errorln();
-        errorln("//-------------------------------------------------------------");
+    if (!ok) {
+        var reduce_options = JSON.parse(options);
+        reduce_options.validate = true;
+        var reduced = reduce_test(original_code, reduce_options, {
+            verbose: false,
+        }).code;
+        if (reduced) {
+            errorln();
+            errorln("// reduced test case (output will differ)");
+            errorln();
+            errorln(reduced);
+            errorln();
+            errorln("//-------------------------------------------------------------");
+        }
     }
     errorln("minify(options):");
     errorln(JSON.stringify(JSON.parse(options), null, 2));

test/ufuzz/job.js

@@ -70,7 +70,7 @@ function run() {
 
     function trap(data) {
         stderr += data;
-        if (~stderr.indexOf("\nminify(options):\n")) {
+        if (~stderr.indexOf("!!!!!! Failed... round ")) {
             process.exitCode = 1;
             child.stderr.removeListener("data", trap);
         }