Adjust for-loop's pattern matching rules (#3308)

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/typ/bugs/3275-loop-errors.typ b/tests/typ/bugs/3275-loop-errors.typ
new file mode 100644
index 00000000..0f05d6af
--- /dev/null
+++ b/tests/typ/bugs/3275-loop-errors.typ
@@ -0,0 +1,49 @@
+// Issue #3275: clearer errors for loops, https://github.com/typst/typst/issues/3275
+// Ref: false
+
+---
+// Normal variable.
+#for x in (1, 2) {}
+#for x in (a: 1, b: 2) {}
+#for x in "foo" {}
+
+---
+// Placeholder.
+#for _ in (1, 2) {}
+#for _ in (a: 1, b: 2) {}
+#for _ in "foo" {}
+
+---
+// Destructuring.
+#for (k, v)  in (("a", 1), ("b", 2), ("c", 3)) {}
+#for (k, ..) in (("a", 1), ("b", 2), ("c", 3)) {}
+#for (k, v)  in (a: 1, b: 2, c: 3) {}
+#for (.., v) in (a: 1, b: 2, c: 3) {}
+
+---
+// Error: 11-17 cannot loop over content
+#for x in [1, 2] {}
+
+---
+// Error: 11-25 cannot loop over bytes
+#for _ in bytes((22, 0)) {}
+
+---
+// Error: 16-21 cannot loop over integer
+#for (x, y) in 12306 {}
+
+---
+// Error: 16-22 cannot loop over content
+#for (x, y) in [1, 2] {}
+
+---
+// Error: 6-12 cannot destructure values of string
+#for (x, y) in "foo" {}
+
+---
+// Error: 6-12 cannot destructure string
+#for (x, y) in ("foo", "bar") {}
+
+---
+// Error: 6-12 cannot destructure integer
+#for (x, y) in (1, 2) {}