added tests for #1107 and a note in the reference

2 files changed, 35 insertions, 0 deletions

diff --git a/test/compile_errors.zig b/test/compile_errors.zig
index 94cd152eb7..592870c678 100644
--- a/test/compile_errors.zig
+++ b/test/compile_errors.zig
@@ -6048,4 +6048,21 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         "tmp.zig:5:30: error: expression value is ignored",
         "tmp.zig:9:30: error: expression value is ignored",
     );
+
+    cases.add(
+        "capture group on switch prong with different payloads",
+        \\const Union = union(enum) {
+        \\    A: usize,
+        \\    B: isize,
+        \\};
+        \\comptime {
+        \\    var u = Union{ .A = 8 };
+        \\    switch (u) {
+        \\        .A, .B => |e| unreachable,
+        \\    }
+        \\}
+    ,
+        "tmp.zig:8:20: error: switch prong contains cases with different payloads",
+        "tmp.zig:8:20: note: payload types are usize and isize",
+    );
 }
diff --git a/test/stage1/behavior/switch.zig b/test/stage1/behavior/switch.zig
index 12e026d0ba..2b7422fa6d 100644
--- a/test/stage1/behavior/switch.zig
+++ b/test/stage1/behavior/switch.zig
@@ -391,3 +391,21 @@ test "switch with null and T peer types and inferred result location type" {
     S.doTheTest(1);
     comptime S.doTheTest(1);
 }
+
+test "switch prongs with cases with identical payloads" {
+    const Union = union(enum) {
+        A: usize,
+        B: isize,
+        C: usize,
+    };
+    const S = struct {
+        fn doTheTest(u: Union) void {
+            switch (u) {
+                .A, .C => |e| expect(@typeOf(e) == usize),
+                .B => |e| expect(@typeOf(e) == isize),
+            }
+        }
+    };
+    S.doTheTest(Union{ .A = 8 });
+    comptime S.doTheTest(Union{ .B = -8 });
+}