Improve diagnostics for duplicated names

codegen/src/rhai_module.rs

@@ -177,7 +177,17 @@ pub(crate) fn check_rename_collisions(fns: &Vec<ExportedFn>) -> Result<(), syn::
             }
         } else {
             let ident = itemfn.name();
-            names.insert(ident.to_string(), ident.span());
+            if let Some(other_span) = names.insert(ident.to_string(), ident.span()) {
+                let mut err = syn::Error::new(
+                    ident.span(),
+                    format!("duplicate function '{}'", ident.to_string()),
+                );
+                err.combine(syn::Error::new(
+                    other_span,
+                    format!("duplicated function '{}'", ident.to_string()),
+                ));
+                return Err(err);
+            }
         }
     }
     for (new_name, attr_span) in renames.drain() {

codegen/ui_tests/rhai_mod_name_collisions.rs

@@ -0,0 +1,31 @@
+use rhai::plugin::*;
+
+#[derive(Clone)]
+pub struct Point {
+    x: f32,
+    y: f32,
+}
+
+#[export_module]
+pub mod test_module {
+    pub use super::Point;
+    pub fn test_fn(input: Point) -> bool {
+        input.x > input.y
+    }
+
+    pub fn test_fn(input: Point) -> bool {
+        input.x < input.y
+    }
+}
+
+fn main() {
+    let n = Point {
+        x: 0.0,
+        y: 10.0,
+    };
+    if test_module::test_fn(n) {
+        println!("yes");
+    } else {
+        println!("no");
+    }
+}

codegen/ui_tests/rhai_mod_name_collisions.stderr

@@ -0,0 +1,17 @@
+error: duplicate function 'test_fn'
+  --> $DIR/rhai_mod_name_collisions.rs:16:12
+   |
+16 |     pub fn test_fn(input: Point) -> bool {
+   |            ^^^^^^^
+
+error: duplicated function 'test_fn'
+  --> $DIR/rhai_mod_name_collisions.rs:12:12
+   |
+12 |     pub fn test_fn(input: Point) -> bool {
+   |            ^^^^^^^
+
+error[E0433]: failed to resolve: use of undeclared type or module `test_module`
+  --> $DIR/rhai_mod_name_collisions.rs:26:8
+   |
+26 |     if test_module::test_fn(n) {
+   |        ^^^^^^^^^^^ use of undeclared type or module `test_module`

codegen/ui_tests/rhai_mod_unknown_type.rs

@@ -0,0 +1,27 @@
+use rhai::plugin::*;
+
+#[derive(Clone)]
+pub struct Point {
+    x: f32,
+    y: f32,
+}
+
+#[export_module]
+pub mod test_module {
+    pub use super::Point;
+    pub fn test_fn(input: Pointer) -> bool {
+        input.x < input.y
+    }
+}
+
+fn main() {
+    let n = Point {
+        x: 0.0,
+        y: 10.0,
+    };
+    if test_module::test_fn(n) {
+        println!("yes");
+    } else {
+        println!("no");
+    }
+}

codegen/ui_tests/rhai_mod_unknown_type.stderr

@@ -0,0 +1,23 @@
+error[E0412]: cannot find type `Pointer` in this scope
+  --> $DIR/rhai_mod_unknown_type.rs:12:27
+   |
+4  | pub struct Point {
+   | ---------------- similarly named struct `Point` defined here
+...
+12 |     pub fn test_fn(input: Pointer) -> bool {
+   |                           ^^^^^^^
+   |
+help: a struct with a similar name exists
+   |
+12 |     pub fn test_fn(input: Point) -> bool {
+   |                           ^^^^^
+help: consider importing one of these items
+   |
+11 |     use core::fmt::Pointer;
+   |
+11 |     use crate::mem::fmt::Pointer;
+   |
+11 |     use std::fmt::Pointer;
+   |
+11 |     use syn::export::fmt::Pointer;
+   |

codegen/ui_tests/rhai_mod_unknown_type_return.rs

@@ -0,0 +1,27 @@
+use rhai::plugin::*;
+
+#[derive(Clone)]
+pub struct Point {
+    x: f32,
+    y: f32,
+}
+
+#[export_module]
+pub mod test_module {
+    pub use super::Point;
+    pub fn test_fn(input: Point) -> boool {
+        input.x < input.y
+    }
+}
+
+fn main() {
+    let n = Point {
+        x: 0.0,
+        y: 10.0,
+    };
+    if test_module::test_fn(n) {
+        println!("yes");
+    } else {
+        println!("no");
+    }
+}

codegen/ui_tests/rhai_mod_unknown_type_return.stderr

@@ -0,0 +1,5 @@
+error[E0412]: cannot find type `boool` in this scope
+  --> $DIR/rhai_mod_unknown_type_return.rs:12:37
+   |
+12 |     pub fn test_fn(input: Point) -> boool {
+   |                                     ^^^^^ help: a builtin type with a similar name exists: `bool`

diag_test/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "diag_test"
+version = "0.1.0"
+authors = ["J Henry Waugh <jhwgh1968@protonmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[[bin]]
+name = "test_template"
+path = "test_template.rs"
+
+[dependencies]
+rhai = { version = "*", path = ".." }

diag_test/test_template.rs

@@ -0,0 +1,35 @@
+use rhai::plugin::*;
+
+#[derive(Clone)]
+pub struct Point {
+    x: f32,
+    y: f32,
+}
+
+#[export_module]
+pub mod test_module {
+    #[rhai_mod(name = "bar")]
+    pub mod test_mod {
+        #[rhai_fn(name = "foo")]
+        pub fn test_fn(input: Point) -> bool {
+            input.x > input.y
+        }
+
+        #[rhai_fn(return_raw)]
+        pub fn test_fn_raw(input: Point) -> Result<rhai::Dynamic, Box<rhai::EvalAltResult>> {
+            Ok(Dynamic::from(input.x > input.y))
+        }
+    }
+}
+
+fn main() {
+    let n = Point {
+        x: 0.0,
+        y: 10.0,
+    };
+    if test_module::test_mod::test_fn(n) {
+        println!("yes");
+    } else {
+        println!("no");
+    }
+}