fix & enhance `collapse_vars` (#4447)

fixes #4446

1 files changed, 38 insertions, 0 deletions

diff --git a/test/compress/default-values.js b/test/compress/default-values.js
index 64dad3cf..8b9b3a95 100644
--- a/test/compress/default-values.js
+++ b/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"
+}