feat(compiler): error diagnostics v2 (#4416)

The Wing compiler now has the capability to provide more detailed information with each compiler error. I've implemented a few examples in this pull request to demonstrate the feature:

Example 1: showing the original symbol definition in "use before defined" errors:
<img width="425" alt="Screenshot 2023-10-04 at 6 34 41 PM" src="https://github.com/winglang/wing/assets/5008987/8749876c-9fd2-455e-9af5-93b4679af492">

Example 2: showing the previous definition in "symbol already defined" errors:
<img width="403" alt="Screenshot 2023-10-04 at 6 36 01 PM" src="https://github.com/winglang/wing/assets/5008987/4106b141-db79-452d-a517-e279b956fb62">

Example 3: showing the variable definition in "variable is not reassignable" errors:
<img width="499" alt="Screenshot 2023-10-04 at 6 31 04 PM" src="https://github.com/winglang/wing/assets/5008987/ea2e2042-6e57-4d4e-b7e0-15bc783edd02">

These errors are also displayed as related information in the LSP with clickable links:
<img width="452" alt="Screenshot 2023-10-04 at 6 21 01 PM" src="https://github.com/winglang/wing/assets/5008987/68680896-adc6-4de7-931e-be2589bc9f08">

I haven't tested what happens when the annotations refer to other files, but in theory it should also work...

## Checklist

- [x] Title matches [Winglang's style guide](https://www.winglang.io/contributing/start-here/pull_requests#how-are-pull-request-titles-formatted)
- [x] Description explains motivation and solution
- [x] Tests added (always)
- [ ] Docs updated (only required for features)
- [ ] Added `pr/e2e-full` label if this feature requires end-to-end testing

*By submitting this pull request, I confirm that my contribution is made under the terms of the [Wing Cloud Contribution License](https://github.com/winglang/wing/blob/main/CONTRIBUTION_LICENSE.md)*.

apps/wing-console/console/server/src/utils/format-wing-error.ts

@@ -42,12 +42,12 @@ export const formatWingError = async (error: unknown) => {
       const result = [];
 
       for (const error of errors) {
-        const { message, span } = error;
+        const { message, span, annotations } = error;
         let files: File[] = [];
         let labels: Label[] = [];
 
         // file_id might be "" if the span is synthetic (see #2521)
-        if (span !== null && span.file_id) {
+        if (span !== null && span !== undefined && span.file_id) {
           // `span` should only be null if source file couldn't be read etc.
           const source = await readFile(span.file_id, "utf8");
           const start = offsetFromLineAndColumn(
@@ -70,6 +70,28 @@ export const formatWingError = async (error: unknown) => {
           });
         }
 
+        for (const annotation of annotations) {
+          const source = await readFile(annotation.span.file_id, "utf8");
+          const start = offsetFromLineAndColumn(
+            source,
+            annotation.span.start.line,
+            annotation.span.start.col,
+          );
+          const end = offsetFromLineAndColumn(
+            source,
+            annotation.span.end.line,
+            annotation.span.end.col,
+          );
+          files.push({ name: annotation.span.file_id, source });
+          labels.push({
+            fileId: annotation.span.file_id,
+            rangeStart: start,
+            rangeEnd: end,
+            message: annotation.message,
+            style: "secondary",
+          });
+        }
+
         console.log("pre diagnostic");
         const diagnosticText = emitDiagnostic(
           files,

apps/wing/src/commands/compile.ts

@@ -54,7 +54,7 @@ export async function compile(entrypoint: string, options: CompileOptions): Prom
       const result = [];
 
       for (const diagnostic of diagnostics) {
-        const { message, span } = diagnostic;
+        const { message, span, annotations } = diagnostic;
         let files: File[] = [];
         let labels: Label[] = [];
 
@@ -74,6 +74,28 @@ export async function compile(entrypoint: string, options: CompileOptions): Prom
           });
         }
 
+        for (const annotation of annotations) {
+          const source = await fsPromise.readFile(annotation.span.file_id, "utf8");
+          const start = byteOffsetFromLineAndColumn(
+            source,
+            annotation.span.start.line,
+            annotation.span.start.col
+          );
+          const end = byteOffsetFromLineAndColumn(
+            source,
+            annotation.span.end.line,
+            annotation.span.end.col
+          );
+          files.push({ name: annotation.span.file_id, source });
+          labels.push({
+            fileId: annotation.span.file_id,
+            rangeStart: start,
+            rangeEnd: end,
+            message: annotation.message,
+            style: "secondary",
+          });
+        }
+
         const diagnosticText = emitDiagnostic(
           files,
           {

apps/wing/src/commands/lsp.ts

@@ -8,6 +8,7 @@ import {
   Diagnostic,
   Range,
   DocumentUri,
+  Location,
 } from "vscode-languageserver/node";
 
 export async function lsp() {
@@ -130,7 +131,17 @@ export async function lsp() {
         const diagnosticUri = "file://" + rd.span.file_id;
         const diag = Diagnostic.create(
           Range.create(rd.span.start.line, rd.span.start.col, rd.span.end.line, rd.span.end.col),
-          rd.message
+          rd.message,
+          undefined,
+          undefined,
+          undefined,
+          rd.annotations.map((a) => ({
+            location: Location.create(
+              "file://" + a.span.file_id,
+              Range.create(a.span.start.line, a.span.start.col, a.span.end.line, a.span.end.col)
+            ),
+            message: a.message,
+          }))
         );
 
         if (!allDiagnostics.has(diagnosticUri)) {

libs/wingc/src/comp_ctx.rs

@@ -110,6 +110,7 @@ pub fn set_custom_panic_hook() {
 				CompilationContext::get_phase()
 			),
 			span: Some(CompilationContext::get_span()),
+			annotations: vec![],
 		})
 	}));
 }

libs/wingc/src/diagnostic.rs

@@ -187,9 +187,16 @@ impl PartialOrd for WingSpan {
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
 pub struct Diagnostic {
 	pub message: String,
+	pub annotations: Vec<DiagnosticAnnotation>,
 	pub span: Option<WingSpan>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
+pub struct DiagnosticAnnotation {
+	pub message: String,
+	pub span: WingSpan,
+}
+
 impl std::fmt::Display for Diagnostic {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		if let Some(span) = &self.span {
@@ -283,6 +290,7 @@ pub fn reset_diagnostics() {
 pub struct TypeError {
 	pub message: String,
 	pub span: WingSpan,
+	pub annotations: Vec<DiagnosticAnnotation>,
 }
 
 impl std::fmt::Display for TypeError {

libs/wingc/src/files.rs

@@ -30,6 +30,7 @@ impl From<FilesError> for Diagnostic {
 		Self {
 			message: err.to_string(),
 			span: None,
+			annotations: vec![],
 		}
 	}
 }

libs/wingc/src/jsify.rs

@@ -404,6 +404,7 @@ impl<'a> JSifier<'a> {
 					report_diagnostic(Diagnostic {
 						message: "Cannot reference an inflight value from within a preflight expression".to_string(),
 						span: Some(expression.span.clone()),
+						annotations: vec![],
 					});
 
 					return "<ERROR>".to_string();
@@ -1089,6 +1090,7 @@ impl<'a> JSifier<'a> {
 							report_diagnostic(Diagnostic {
 								message: format!("Failed to resolve extern \"{external_spec}\": {err}"),
 								span: Some(func_def.span.clone()),
+								annotations: vec![],
 							});
 							format!("/* unresolved: \"{external_spec}\" */")
 						}

libs/wingc/src/json_schema_generator.rs

@@ -25,7 +25,7 @@ impl JsonSchemaGenerator {
 	fn get_struct_schema_required_fields(&self, env: &SymbolEnv) -> CodeMaker {
 		let mut code = CodeMaker::default();
 		code.open("required: [");
-		for (field_name, (_stmt_idx, kind)) in env.symbol_map.iter() {
+		for (field_name, (_stmt_idx, _, kind)) in env.symbol_map.iter() {
 			if !matches!(*kind.as_variable().unwrap().type_, Type::Optional(_)) {
 				code.line(format!("\"{}\",", field_name));
 			}

libs/wingc/src/lib.rs

@@ -165,6 +165,7 @@ pub unsafe extern "C" fn wingc_compile(ptr: u32, len: u32) -> u64 {
 		report_diagnostic(Diagnostic {
 			message: format!("Expected 3 arguments to wingc_compile, got {}", split.len()),
 			span: None,
+			annotations: vec![],
 		});
 		return WASM_RETURN_ERROR;
 	}
@@ -176,6 +177,7 @@ pub unsafe extern "C" fn wingc_compile(ptr: u32, len: u32) -> u64 {
 		report_diagnostic(Diagnostic {
 			message: format!("Source path cannot be found: {}", source_path),
 			span: None,
+			annotations: vec![],
 		});
 		return WASM_RETURN_ERROR;
 	}
@@ -338,6 +340,7 @@ pub fn compile(
 		report_diagnostic(Diagnostic {
 			message: format!("Project directory must be absolute: {}", project_dir),
 			span: None,
+			annotations: vec![],
 		});
 		return Err(());
 	}

libs/wingc/src/lifting.rs

@@ -56,11 +56,12 @@ impl<'a> LiftVisitor<'a> {
 		if let Some(env) = self.ctx.current_env() {
 			if matches!(
 				env.lookup_ext(symbol, Some(self.ctx.current_stmt_idx())),
-				LookupResult::DefinedLater
+				LookupResult::DefinedLater(_)
 			) {
 				report_diagnostic(Diagnostic {
 					span: Some(symbol.span.clone()),
 					message: format!("Cannot access \"{symbol}\" because it is shadowed by another symbol with the same name"),
+					annotations: vec![],
 				});
 			}
 		}
@@ -215,6 +216,7 @@ impl<'a> Visit<'a> for LiftVisitor<'a> {
 							expr_type.to_string()
 						),
 						span: Some(node.span.clone()),
+						annotations: vec![],
 					});
 
 					return;
@@ -279,6 +281,7 @@ impl<'a> Visit<'a> for LiftVisitor<'a> {
 					message: format!(
 						"Cannot qualify access to a lifted type \"{udt_type}\" (see https://github.com/winglang/wing/issues/76 for more details)"),
 					span: Some(node.span.clone()),
+					annotations: vec![],
 				});
 
 				return;

libs/wingc/src/lsp/completions.rs

@@ -510,7 +510,7 @@ fn get_current_scope_completions(
 			true
 		}
 	}) {
-		let symbol_kind = &symbol_data.1 .1;
+		let symbol_kind = &symbol_data.1 .2;
 
 		if let Some(completion) = format_symbol_kind_as_completion(symbol_data.0, symbol_kind) {
 			completions.push(completion);
@@ -731,7 +731,7 @@ fn get_completions_from_namespace(
 		.envs
 		.iter()
 		.flat_map(|env| env.symbol_map.iter())
-		.flat_map(|(name, symbol)| format_symbol_kind_as_completion(name, &symbol.1))
+		.flat_map(|(name, symbol)| format_symbol_kind_as_completion(name, &symbol.2))
 		.chain(util_completions.into_iter())
 		.collect()
 }

libs/wingc/src/parser.rs

@@ -203,6 +203,7 @@ pub fn parse_wing_project(
 					formatted_cycle.trim_end()
 				),
 				span: None,
+				annotations: vec![],
 			});
 
 			// return a list of all files just so we can continue type-checking
@@ -359,6 +360,7 @@ impl<'s> Parser<'s> {
 		let diag = Diagnostic {
 			message: message.to_string(),
 			span: Some(span),
+			annotations: vec![],
 		};
 		report_diagnostic(diag);
 	}
@@ -367,6 +369,7 @@ impl<'s> Parser<'s> {
 		let diag = Diagnostic {
 			message: message.to_string(),
 			span: Some(self.node_span(node)),
+			annotations: vec![],
 		};
 		report_diagnostic(diag);
 
@@ -996,6 +999,7 @@ impl<'s> Parser<'s> {
 							message: "Static class fields not supported yet, see https://github.com/winglang/wing/issues/1668"
 								.to_string(),
 							span: Some(self.node_span(&class_element)),
+							annotations: vec![],
 						});
 					}
 
@@ -2115,6 +2119,7 @@ impl<'s> Parser<'s> {
 				let diag = Diagnostic {
 					message: "Expected ';'".to_string(),
 					span: Some(self.node_span(&target_node)),
+					annotations: vec![],
 				};
 				report_diagnostic(diag);
 			} else if node.kind() == "AUTOMATIC_BLOCK" {
@@ -2135,6 +2140,7 @@ impl<'s> Parser<'s> {
 					let diag = Diagnostic {
 						message: format!("Expected '{}'", node.kind()),
 						span: Some(self.node_span(&target_node)),
+						annotations: vec![],
 					};
 					report_diagnostic(diag);
 				}