fix `collapse_vars` on `switch` (#2578)

1 files changed, 57 insertions, 1 deletions

diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index ab86c6b4..2136b2f0 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -1749,7 +1749,7 @@ for_init: {
     }
 }
 
-switch_case: {
+switch_case_1: {
     options = {
         collapse_vars: true,
         unused: true,
@@ -1777,6 +1777,62 @@ switch_case: {
     }
 }
 
+switch_case_2: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 1, b = 2;
+        switch (b++) {
+          case b:
+            var c = a;
+            var a;
+            break;
+        }
+        console.log(a);
+    }
+    expect: {
+        var a = 1, b = 2;
+        switch (b++) {
+          case b:
+            var c = a;
+            var a;
+            break;
+        }
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+switch_case_3: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 1, b = 2;
+        switch (a) {
+          case a:
+            var b;
+            break;
+          case b:
+            break;
+        }
+        console.log(b);
+    }
+    expect: {
+        var a = 1, b = 2;
+        switch (a) {
+          case a:
+            var b;
+            break;
+          case b:
+            break;
+        }
+        console.log(b);
+    }
+    expect_stdout: "2"
+}
+
 issue_27: {
     options = {
         collapse_vars: true,