better errors for type arguments of collections

3 files changed, 16 insertions, 3 deletions

diff --git a/ui-tests/src/bin/unconvertible_type_map.rs b/ui-tests/src/bin/unconvertible_type_map.rs
new file mode 100644
index 0000000..40f883b
--- /dev/null
+++ b/ui-tests/src/bin/unconvertible_type_map.rs
@@ -0,0 +1,8 @@
+#[dynamize::dynamize]
+trait Trait {
+    type A: Into<String>;
+
+    fn a(&self) -> HashMap<Self::A>;
+}
+
+fn main() {}
diff --git a/ui-tests/src/bin/unconvertible_type_map.stderr b/ui-tests/src/bin/unconvertible_type_map.stderr
new file mode 100644
index 0000000..a6833d2
--- /dev/null
+++ b/ui-tests/src/bin/unconvertible_type_map.stderr
@@ -0,0 +1,5 @@
+error: dynamize expects at least 2 generic type arguments for this type
+ --> src/bin/unconvertible_type_map.rs:5:20
+  |
+5 |     fn a(&self) -> HashMap<Self::A>;
+  |                    ^^^^^^^
diff --git a/ui-tests/src/bin/unconvertible_type_vec.stderr b/ui-tests/src/bin/unconvertible_type_vec.stderr
index 65306f0..f966ede 100644
--- a/ui-tests/src/bin/unconvertible_type_vec.stderr
+++ b/ui-tests/src/bin/unconvertible_type_vec.stderr
@@ -1,5 +1,5 @@
-error: dynamize does not know how to convert this type
- --> src/bin/unconvertible_type_vec.rs:5:20
+error: for Vec dynamize supports associated types only within the first 1 generic type parameters
+ --> src/bin/unconvertible_type_vec.rs:5:32
   |
 5 |     fn a(&self) -> Vec<String, Self::A>;
-  |                    ^^^
+  |                                ^^^^