Show source names in diagnostics

crates/decodal-wasm/src/lib.rs

@@ -1,7 +1,8 @@
 use std::collections::BTreeMap;
 
 use decodal_core::{
-    Data, Diagnostic, DiagnosticKind, EmptyLoader, Engine, LoadedSource, SourceLoader, Span,
+    Data, Diagnostic, DiagnosticKind, EmptyLoader, Engine, LoadedSource, SourceId, SourceLoader,
+    Span, format_diagnostic_with,
 };
 use wasm_bindgen::prelude::*;
 
@@ -24,11 +25,18 @@ fn encode_result(result: Result<String, String>) -> String {
 
 fn evaluate_inner(source: &str) -> Result<String, String> {
     let mut engine = Engine::new(EmptyLoader);
-    let module = engine
-        .add_root_source("playground", "playground", source)
-        .map_err(format_diagnostic)?;
-    let value = engine.eval_module(module).map_err(format_diagnostic)?;
-    let data = engine.materialize(&value).map_err(format_diagnostic)?;
+    let module = match engine.add_root_source("playground", "playground", source) {
+        Ok(module) => module,
+        Err(error) => return Err(format_diagnostic_with_root(&error, "playground")),
+    };
+    let value = match engine.eval_module(module) {
+        Ok(value) => value,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
+    let data = match engine.materialize(&value) {
+        Ok(data) => data,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
     Ok(format_data(&data, 0))
 }
 
@@ -48,11 +56,18 @@ fn evaluate_project_inner(entry: &str, files_json: &str) -> Result<String, Strin
         .ok_or_else(|| format!("entry file `{entry}` was not found"))?;
 
     let mut engine = Engine::new(VirtualLoader { files });
-    let module = engine
-        .add_root_source(entry.clone(), entry.clone(), &source)
-        .map_err(format_diagnostic)?;
-    let value = engine.eval_module(module).map_err(format_diagnostic)?;
-    let data = engine.materialize(&value).map_err(format_diagnostic)?;
+    let module = match engine.add_root_source(entry.clone(), entry.clone(), &source) {
+        Ok(module) => module,
+        Err(error) => return Err(format_diagnostic_with_root(&error, &entry)),
+    };
+    let value = match engine.eval_module(module) {
+        Ok(value) => value,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
+    let data = match engine.materialize(&value) {
+        Ok(data) => data,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
     Ok(format_data(&data, 0))
 }
 
@@ -124,22 +139,10 @@ fn normalize_path(path: &str) -> Option<String> {
     }
 }
 
-fn format_diagnostic(diagnostic: decodal_core::Diagnostic) -> String {
-    let mut out = format!(
-        "{:?} at {}:{}..{}: {}",
-        diagnostic.kind,
-        diagnostic.span.source.0,
-        diagnostic.span.start,
-        diagnostic.span.end,
-        diagnostic.message,
-    );
-    for label in diagnostic.labels {
-        out.push_str(&format!(
-            "\nnote at {}:{}..{}: {}",
-            label.span.source.0, label.span.start, label.span.end, label.message,
-        ));
-    }
-    out
+fn format_diagnostic_with_root(diagnostic: &decodal_core::Diagnostic, root_name: &str) -> String {
+    format_diagnostic_with(diagnostic, |source| {
+        (source == SourceId(0)).then_some(root_name)
+    })
 }
 
 fn format_data(data: &Data, indent: usize) -> String {
@@ -237,4 +240,17 @@ mod tests {
         let output = evaluate_project_inner("main.dcdl", files).unwrap();
         assert!(output.contains("\"port\": 9443"));
     }
+
+    #[test]
+    fn project_diagnostics_use_virtual_file_names() {
+        let files = r#"{
+            "main.dcdl":"let dep = import \"./schemas/service.dcdl\"; in dep.Service & { port = 80; }",
+            "schemas/service.dcdl":"Service = { port = Int & > 443 default 8443; }"
+        }"#;
+        let error = evaluate_project_inner("main.dcdl", files).unwrap_err();
+        assert!(error.contains("main.dcdl:"));
+        assert!(error.contains("schemas/service.dcdl:"));
+        assert!(!error.contains("source 0:"));
+        assert!(!error.contains("source 1:"));
+    }
 }