only show relevant labels

compiler-core/src/type_/fields.rs

···
 
         if self.arity as usize != args.len() {
             return Err(Error::IncorrectArity {
-                labels: self.incorrect_arity_labels(args),
+                labels: self.missing_labels(args),
                 location,
                 context,
                 expected: self.arity as usize,
···
         }
     }
 
-    pub fn incorrect_arity_labels<A>(&self, args: &[CallArg<A>]) -> Vec<EcoString> {
-        let given: HashSet<_> = args.iter().filter_map(|arg| arg.label.as_ref()).collect();
-
-        self.fields
-            .keys()
-            .filter(|f| !given.contains(f))
-            .cloned()
-            .sorted()
-            .collect()
-    }
-
     /// This returns an array of the labels that are unused given an argument
     /// list.
     /// The unused labels are in the order they are expected to be passed in
···
     /// wibble(1, label3: 2) // -> unused labels: [label2]
     /// ```
     ///
-    pub fn missing_labels<A: std::fmt::Debug>(&self, args: &[CallArg<A>]) -> Vec<EcoString> {
+    pub fn missing_labels<A>(&self, args: &[CallArg<A>]) -> Vec<EcoString> {
         // We need to know how many positional arguments are in the function
         // arguments. That's given by the position of the first labelled
         // argument; if the first label argument is third, then we know the

compiler-core/src/type_/tests/errors.rs

···
 "
     );
 }
+
+// https://github.com/gleam-lang/gleam/issues/3884
+#[test]
+fn show_only_missing_labels() {
+    assert_module_error!(
+        "
+fn wibble(a a: Int, b b: Float, c c: String) {
+    todo
+}
+
+pub fn wobble() {
+    wibble(1, 2.0)
+}
+"
+    );
+}

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__errors__guard_record_wrong_arity.snap

···
 
 This call accepts these additional labelled arguments:
 
-  - a
   - b

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__errors__show_only_missing_labels.snap

···
+---
+source: compiler-core/src/type_/tests/errors.rs
+expression: "\nfn wibble(a a: Int, b b: Float, c c: String) {\n    todo\n}\n\npub fn wobble() {\n    wibble(1, 2.0)\n}\n"
+---
+----- SOURCE CODE
+
+fn wibble(a a: Int, b b: Float, c c: String) {
+    todo
+}
+
+pub fn wobble() {
+    wibble(1, 2.0)
+}
+
+
+----- ERROR
+error: Incorrect arity
+  ┌─ /src/one/two.gleam:7:5
+  │
+7 │     wibble(1, 2.0)
+  │     ^^^^^^^^^^^^^^ Expected 3 arguments, got 2
+
+This call accepts these additional labelled arguments:
+
+  - c

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__functions__function_call_incorrect_arity_with_label_shorthand_fault_tolerance2.snap

···
 This call accepts these additional labelled arguments:
 
   - wabble
-  - wibble
 
 error: Type mismatch
   ┌─ /src/one/two.gleam:8:10

compiler-core/src/type_/tests/snapshots/gleam_core__type___tests__functions__function_call_incorrect_arity_with_labels_fault_tolerance2.snap

···
 This call accepts these additional labelled arguments:
 
   - wabble
-  - wibble
 
 error: Type mismatch
   ┌─ /src/one/two.gleam:7:10