refactor: improve empty module validation and warnings

Author: vitorsouzaalmeida

compiler-core/src/build/package_compiler.rs

@@ -578,7 +578,9 @@ fn analyse(
                     .filter(|def| def.is_public())
                     .count();
 
-                if public_definitions == 0 {
+                // Only emit the empty module warning if the module has no definitions at all.
+                // Modules with only private definitions already emit their own warnings.
+                if public_definitions == 0 && module.ast.definitions.is_empty() {
                     warnings.emit(crate::warning::Warning::EmptyModule {
                         path: module.input_path.clone(),
                         name: module.name.clone(),

compiler-core/src/error.rs

@@ -1052,13 +1052,12 @@ Please make sure internal types do not appear in public functions and try again.
 
             Error::CannotPublishEmptyModules { unfinished } => vec![Diagnostic {
                 title: "Cannot publish empty modules".into(),
-                text: format!(
+                text: wrap_format!(
                     "These modules contain no public definitions and cannot be published:
 
 {}
 
-Please add public functions, types, or constants to these modules, or remove them and try again.
-",
+Please add public functions, types, or constants to these modules, or remove them and try again.",
                     unfinished
                         .iter()
                         .map(|name| format!("  - {}", name.as_str()))

compiler-core/src/warning.rs

@@ -1396,20 +1396,12 @@ The imported value could not be used in this module anyway."
                 }
             }
 
-            Warning::EmptyModule { path, name } => Diagnostic {
+            Warning::EmptyModule { path: _, name } => Diagnostic {
                 title: "Empty module".into(),
                 text: format!("Module '{name}' contains no public definitions."),
                 hint: Some("Consider adding public functions, types, or constants, or removing this module.".into()),
                 level: diagnostic::Level::Warning,
-                location: Some(Location {
-                    label: diagnostic::Label {
-                        text: Some("This module is empty".into()),
-                        span: SrcSpan { start: 0, end: 0 },
-                    },
-                    path: path.clone(),
-                    src: EcoString::from(""),
-                    extra_labels: vec![],
-                }),
+                location: None,
             },
         }
     }

test-package-compiler/cases/empty_module_publish_validation/gleam.toml renamed to test-package-compiler/cases/empty_module_warning/gleam.toml

@@ -1,4 +1,4 @@
-name = "empty_module_publish_validation"
+name = "empty_module_warning"
 version = "1.0.0"
 description = "Test package with empty modules"
 licences = ["Apache-2.0"]

test-package-compiler/cases/empty_module_publish_validation/src/empty.gleam renamed to test-package-compiler/cases/empty_module_warning/src/empty.gleam

@@ -1,6 +1,6 @@
 ---
 source: test-package-compiler/src/generated_tests.rs
-expression: "./cases/empty_module_publish_validation"
+expression: "./cases/empty_module_warning"
 snapshot_kind: text
 ---
 //// /out/lib/the_package/_gleam_artefacts/empty.cache
@@ -31,8 +31,8 @@ main() ->
     <<"This module has public definitions"/utf8>>.
 
 
-//// /out/lib/the_package/ebin/empty_module_publish_validation.app
-{application, empty_module_publish_validation, [
+//// /out/lib/the_package/ebin/empty_module_warning.app
+{application, empty_module_warning, [
     {vsn, "1.0.0"},
     {applications, [gleam_stdlib]},
     {description, "Test package with empty modules"},
@@ -44,10 +44,6 @@ main() ->
 
 //// Warning
 warning: Empty module
-  ┌─ src/empty.gleam:1:1
-  │
-1 │ 
-  │ ^ This module is empty
 
 Module 'empty' contains no public definitions.
 Hint: Consider adding public functions, types, or constants, or removing this module.

test-package-compiler/cases/empty_module_publish_validation/src/main.gleam renamed to test-package-compiler/cases/empty_module_warning/src/main.gleam

@@ -34,10 +34,6 @@ snapshot_kind: text
 
 //// Warning
 warning: Empty module
-  ┌─ src/main.gleam:1:1
-  │
-1 │ 
-  │ ^ This module is empty
 
 Module 'main' contains no public definitions.
 Hint: Consider adding public functions, types, or constants, or removing this module.

test-package-compiler/src/generated_tests.rs

@@ -28,10 +28,6 @@ snapshot_kind: text
 
 //// Warning
 warning: Empty module
-  ┌─ src/empty.gleam:1:1
-  │
-1 │ 
-  │ ^ This module is empty
 
 Module 'empty' contains no public definitions.
 Hint: Consider adding public functions, types, or constants, or removing this module.