feat: include Go compilation warnings and errors in the LSP diagnostics

cmd/lspcmd/handler.go

@@ -84,17 +84,26 @@ func (p *Proxy) sendToClient(r toClientRequest) {
 func (p *Proxy) proxyFromGoplsToClient(ctx context.Context, conn *jsonrpc2.Conn, r *jsonrpc2.Request) {
 	p.log.Info("gopls -> client", zap.String("method", r.Method), zap.Bool("notif", r.Notif))
 	if r.Notif {
-		p.log.Info("gopls -> client: notification", zap.String("method", r.Method), zap.Bool("notif", r.Notif))
-		if r.Method == "window/showMessage" && p.shouldSuppressWindowShowMessage(r) {
+		var err error
+		switch r.Method {
+		case "window/showMessage":
+			if p.shouldSuppressWindowShowMessage(r) {
+				return
+			}
+		case "textDocument/publishDiagnostics":
+			err = p.rewriteGoplsPublishDiagnostics(r)
+		}
+		if err != nil {
+			p.log.Error("gopls -> client: error rewriting notification", zap.Error(err))
 			return
 		}
-		err := p.client.Notify(ctx, r.Method, r.Params)
+		err = p.client.Notify(ctx, r.Method, r.Params)
 		if err != nil {
-			p.log.Error("gopls to client: notification: send error", zap.Error(err))
+			p.log.Error("gopls -> client: notification: send error", zap.Error(err))
+			return
 		}
 		p.log.Info("gopls -> client: notification: complete")
 	} else {
-		p.log.Info("gopls -> client: call", zap.String("method", r.Method), zap.Bool("notif", r.Notif), zap.Any("params", r.Params))
 		var result map[string]interface{}
 		err := p.client.Call(ctx, r.Method, &r.Params, &result)
 		if err != nil {
@@ -118,6 +127,43 @@ func (p *Proxy) shouldSuppressWindowShowMessage(r *jsonrpc2.Request) (shouldIgno
 	return strings.HasPrefix(params.Message, "Do not edit this file!")
 }
 
+func (p *Proxy) rewriteGoplsPublishDiagnostics(r *jsonrpc2.Request) (err error) {
+	// Unmarshal the params.
+	var params lsp.PublishDiagnosticsParams
+	if err = json.Unmarshal(*r.Params, &params); err != nil {
+		return err
+	}
+	// Get the sourcemap from the cache.
+	uri := strings.TrimSuffix(string(params.URI), "_templ.go") + ".templ"
+	sourceMap, ok := p.sourceMapCache.Get(uri)
+	if !ok {
+		return fmt.Errorf("unable to complete because the sourcemap for %q doesn't exist in the cache, has the didOpen notification been sent yet?", uri)
+	}
+	params.URI = lsp.DocumentURI(uri)
+	// Rewrite the positions.
+	for i := 0; i < len(params.Diagnostics); i++ {
+		item := params.Diagnostics[i]
+		start, _, ok := sourceMap.SourcePositionFromTarget(item.Range.Start.Line+1, item.Range.Start.Character)
+		if ok {
+			item.Range.Start.Line = start.Line - 1
+			item.Range.Start.Character = start.Col + 1
+		}
+		end, _, ok := sourceMap.SourcePositionFromTarget(item.Range.End.Line+1, item.Range.End.Character)
+		if ok {
+			item.Range.End = templatePositionToLSPPosition(end)
+		}
+		params.Diagnostics[i] = item
+	}
+	// Marshal the params back.
+	jsonMessage, err := json.Marshal(params)
+	if err != nil {
+		return
+	}
+	err = r.Params.UnmarshalJSON(jsonMessage)
+	// Done.
+	return err
+}
+
 // Handle implements jsonrpc2.Handler. This function receives from the text editor client, and calls the proxy function
 // to determine how to play it back to the client.
 func (p *Proxy) Handle(ctx context.Context, conn *jsonrpc2.Conn, r *jsonrpc2.Request) {
@@ -231,7 +277,7 @@ func (p *Proxy) rewriteCompletionResponse(uri string, resp *lsp.CompletionList)
 	uri = strings.TrimSuffix(uri, "_templ.go") + ".templ"
 	sourceMap, ok := p.sourceMapCache.Get(uri)
 	if !ok {
-		return fmt.Errorf("unable to complete because the sourcemap doesn't exist in the cache, has the didOpen notification been sent yet?")
+		return fmt.Errorf("unable to complete because the sourcemap for %q doesn't exist in the cache, has the didOpen notification been sent yet?", uri)
 	}
 	// Rewrite the positions.
 	for i := 0; i < len(resp.Items); i++ {
@@ -263,7 +309,7 @@ func (p *Proxy) rewriteCompletionRequest(params *lsp.CompletionParams) (err erro
 	// Get the sourcemap from the cache.
 	sourceMap, ok := p.sourceMapCache.Get(string(params.TextDocument.URI))
 	if !ok {
-		return fmt.Errorf("unable to complete because the sourcemap doesn't exist in the cache, has the didOpen notification been sent yet?")
+		return fmt.Errorf("unable to complete because the sourcemap for %q doesn't exist in the cache, has the didOpen notification been sent yet?", params.TextDocument.URI)
 	}
 	// Map from the source position to target Go position.
 	to, mapping, ok := sourceMap.TargetPositionFromSource(params.Position.Line+1, params.Position.Character)