1 files changed, 58 insertions, 0 deletions
diff --git a/tests/generics/tgenericwhen.nim b/tests/generics/tgenericwhen.nim
new file mode 100644
index 000000000..87672a699
--- /dev/null
+++ b/tests/generics/tgenericwhen.nim
@@ -0,0 +1,58 @@
+discard """
+  targets: "c js"
+"""
+
+block: # issue #24041
+  type ArrayBuf[N: static int, T = byte] = object
+    when sizeof(int) > sizeof(uint8):
+      when N <= int(uint8.high):
+        n: uint8
+      else:
+        when sizeof(int) > sizeof(uint16):
+          when N <= int(uint16.high):
+            n: uint16
+          else:
+            when sizeof(int) > sizeof(uint32):
+              when N <= int(uint32.high):
+                n: uint32
+              else:
+                n: int
+            else:
+              n: int
+        else:
+          n: int
+    else:
+      n: int
+
+  var x: ArrayBuf[8]
+  doAssert x.n is uint8
+  when sizeof(int) > sizeof(uint32):
+    var y: ArrayBuf[int(uint32.high) * 8]
+    doAssert y.n is int
+
+block: # constant condition after dynamic one
+  type Foo[T] = object
+    when T is int:
+      a: int
+    elif true:
+      a: string
+    else:
+      a: bool
+  var x: Foo[string]
+  doAssert x.a is string
+  var y: Foo[int]
+  doAssert y.a is int
+  var z: Foo[float]
+  doAssert z.a is string
+
+block: # issue #4774, but not with threads
+  const hasThreadSupport = not defined(js)
+  when hasThreadSupport:
+    type Channel[T] = object
+      value: T
+  type
+    SomeObj[T] = object
+      when hasThreadSupport:
+        channel: ptr Channel[T]
+  var x: SomeObj[int]
+  doAssert compiles(x.channel) == hasThreadSupport