Better errors for array/dictionary method calls that return mutable (#3370)

1 files changed, 109 insertions, 0 deletions

diff --git a/tests/typ/bugs/3154-array-dict-mut-entry.typ b/tests/typ/bugs/3154-array-dict-mut-entry.typ
new file mode 100644
index 00000000..b5a52814
--- /dev/null
+++ b/tests/typ/bugs/3154-array-dict-mut-entry.typ
@@ -0,0 +1,109 @@
+// Issue #3154: Confusing errors from methods supposed to return a mutable entry
+// https://github.com/typst/typst/issues/3154
+// Ref: false
+
+---
+#{
+  let array = ()
+  // Error: 3-16 array is empty
+  array.first()
+}
+
+---
+#{
+  let array = ()
+  // Error: 3-16 array is empty
+  array.first() = 9
+}
+
+---
+#{
+  let array = ()
+  // Error: 3-15 array is empty
+  array.last()
+}
+
+---
+#{
+  let array = ()
+  // Error: 3-15 array is empty
+  array.last() = 9
+}
+
+---
+#{
+  let array = (1,)
+  // Error: 3-14 array index out of bounds (index: 1, len: 1) and no default value was specified
+  array.at(1)
+}
+
+---
+#{
+  let array = (1,)
+  test(array.at(1, default: 0), 0)
+}
+
+---
+#{
+  let array = (1,)
+  // Error: 3-14 array index out of bounds (index: 1, len: 1)
+  array.at(1) = 9
+}
+
+---
+#{
+  let array = (1,)
+  // Error: 3-26 array index out of bounds (index: 1, len: 1)
+  array.at(1, default: 0) = 9
+}
+
+---
+#{
+  let dict = (a: 1)
+  // Error: 3-15 dictionary does not contain key "b" and no default value was specified
+  dict.at("b")
+}
+
+---
+#{
+  let dict = (a: 1)
+  test(dict.at("b", default: 0), 0)
+}
+
+---
+#{
+  let dict = (a: 1)
+  // Error: 3-15 dictionary does not contain key "b"
+  // Hint: 3-15 use `insert` to add or update values
+  dict.at("b") = 9
+}
+
+---
+#{
+  let dict = (a: 1)
+  // Error: 3-27 dictionary does not contain key "b"
+  // Hint: 3-27 use `insert` to add or update values
+  dict.at("b", default: 0) = 9
+}
+
+---
+#{
+  let dict = (a: 1)
+  // Error: 8-9 dictionary does not contain key "b"
+  dict.b
+}
+
+---
+#{
+  let dict = (a: 1)
+  dict.b = 9
+  test(dict, (a: 1, b: 9))
+}
+
+---
+#{
+  let dict = (a: 1)
+  // Error: 3-9 dictionary does not contain key "b"
+  // Hint: 3-9 use `insert` to add or update values
+  dict.b += 9
+}