lsp: Correctly handle URIs and paths on Windows (#569)

* lsp: Correctly handle URIs and paths on Windows

Signed-off-by: Charlie Egan <[email protected]>

* Appease linter

Signed-off-by: Charlie Egan <[email protected]>

* Add tests for generic client URI behaviour

Signed-off-by: Charlie Egan <[email protected]>

---------

Signed-off-by: Charlie Egan <[email protected]>

internal/lsp/cache.go

@@ -2,7 +2,6 @@ package lsp
 
 import (
 	"fmt"
-	"net/url"
 	"os"
 	"sync"
 
@@ -196,17 +195,8 @@ func (c *Cache) Delete(uri string) {
 	c.diagnosticsParseMu.Unlock()
 }
 
-func updateCacheForURIFromDisk(cache *Cache, uri string) (string, error) {
-	parsedURI, err := url.Parse(uri)
-	if err != nil {
-		return "", fmt.Errorf("failed to parse URI: %w", err)
-	}
-
-	if parsedURI.Scheme != "file" {
-		return "", fmt.Errorf("only file:// URIs are supported, got %q", parsedURI.String())
-	}
-
-	content, err := os.ReadFile(parsedURI.Path)
+func updateCacheForURIFromDisk(cache *Cache, uri, path string) (string, error) {
+	content, err := os.ReadFile(path)
 	if err != nil {
 		return "", fmt.Errorf("failed to read file: %w", err)
 	}

internal/lsp/clients/clients.go

@@ -0,0 +1,18 @@
+package clients
+
+// Identifier represent different supported clients and can be used to toggle or change
+// server behavior based on the client.
+type Identifier int
+
+const (
+	IdentifierGeneric Identifier = iota
+	IdentifierVSCode
+)
+
+func DetermineClientIdentifier(clientName string) Identifier {
+	if clientName == "Visual Studio Code" {
+		return IdentifierVSCode
+	}
+
+	return IdentifierGeneric
+}

internal/lsp/messages.go

@@ -120,6 +120,15 @@ type TextDocumentIdentifier struct {
 	URI string `json:"uri"`
 }
 
+type TextDocumentDidChangeParams struct {
+	TextDocument   TextDocumentIdentifier           `json:"textDocument"`
+	ContentChanges []TextDocumentContentChangeEvent `json:"contentChanges"`
+}
+
+type TextDocumentContentChangeEvent struct {
+	Text string `json:"text"`
+}
+
 type Diagnostic struct {
 	Range    Range          `json:"range"`
 	Message  string         `json:"message"`

internal/lsp/server.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -15,6 +14,8 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 	"gopkg.in/yaml.v3"
 
+	"github.com/styrainc/regal/internal/lsp/clients"
+	"github.com/styrainc/regal/internal/lsp/uri"
 	"github.com/styrainc/regal/pkg/config"
 )
 
@@ -51,7 +52,16 @@ type LanguageServer struct {
 	diagnosticRequestFile      chan fileDiagnosticRequiredEvent
 	diagnosticRequestWorkspace chan string
 
-	clientRootURI string
+	clientRootURI    string
+	clientIdentifier clients.Identifier
+}
+
+// fileDiagnosticRequiredEvent is sent to the diagnosticRequestFile channel when
+// diagnostics are required for a file.
+type fileDiagnosticRequiredEvent struct {
+	Reason  string
+	URI     string
+	Content string
 }
 
 func (l *LanguageServer) Handle(
@@ -256,14 +266,6 @@ func (l *LanguageServer) logOutboundMessage(method string, message any) {
 	}
 }
 
-// fileDiagnosticRequiredEvent is sent to the diagnosticRequestFile channel when
-// diagnostics are required for a file.
-type fileDiagnosticRequiredEvent struct {
-	Reason  string
-	URI     string
-	Content string
-}
-
 func (l *LanguageServer) handleTextDocumentDidOpen(
 	_ context.Context,
 	_ *jsonrpc2.Conn,
@@ -283,15 +285,6 @@ func (l *LanguageServer) handleTextDocumentDidOpen(
 	return struct{}{}, nil
 }
 
-type TextDocumentDidChangeParams struct {
-	TextDocument   TextDocumentIdentifier           `json:"textDocument"`
-	ContentChanges []TextDocumentContentChangeEvent `json:"contentChanges"`
-}
-
-type TextDocumentContentChangeEvent struct {
-	Text string `json:"text"`
-}
-
 func (l *LanguageServer) handleTextDocumentDidChange(
 	_ context.Context,
 	_ *jsonrpc2.Conn,
@@ -322,7 +315,11 @@ func (l *LanguageServer) handleWorkspaceDidCreateFiles(
 	}
 
 	for _, createOp := range params.Files {
-		_, err = updateCacheForURIFromDisk(l.cache, createOp.URI)
+		_, err = updateCacheForURIFromDisk(
+			l.cache,
+			uri.FromPath(l.clientIdentifier, createOp.URI),
+			uri.ToPath(l.clientIdentifier, createOp.URI),
+		)
 		if err != nil {
 			return nil, fmt.Errorf("failed to update cache for uri %q: %w", createOp.URI, err)
 		}
@@ -369,7 +366,11 @@ func (l *LanguageServer) handleWorkspaceDidRenameFiles(
 	}
 
 	for _, renameOp := range params.Files {
-		content, err := updateCacheForURIFromDisk(l.cache, renameOp.NewURI)
+		content, err := updateCacheForURIFromDisk(
+			l.cache,
+			uri.FromPath(l.clientIdentifier, renameOp.NewURI),
+			uri.ToPath(l.clientIdentifier, renameOp.NewURI),
+		)
 		if err != nil {
 			return nil, fmt.Errorf("failed to update cache for uri %q: %w", renameOp.NewURI, err)
 		}
@@ -418,6 +419,13 @@ func (l *LanguageServer) handleInitialize(
 	}
 
 	l.clientRootURI = params.RootURI
+	l.clientIdentifier = clients.DetermineClientIdentifier(params.ClientInfo.Name)
+
+	if l.clientIdentifier == clients.IdentifierGeneric {
+		l.log(
+			"Unable to match client identifier for initializing client, using generic functionality: " + params.ClientInfo.Name,
+		)
+	}
 
 	regoFilter := FileOperationFilter{
 		Scheme: "file",
@@ -453,36 +461,35 @@ func (l *LanguageServer) handleInitialize(
 		},
 	}
 
-	folderURI, err := url.Parse(l.clientRootURI)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse URI: %w", err)
-	}
+	workspaceRootPath := uri.ToPath(l.clientIdentifier, l.clientRootURI)
 
 	// load the rego source files into the cache
-	err = filepath.WalkDir(folderURI.Path, func(path string, d os.DirEntry, err error) error {
+	err = filepath.WalkDir(workspaceRootPath, func(path string, d os.DirEntry, err error) error {
 		if err != nil {
-			return fmt.Errorf("failed to walk workspace dir %q: %w", folderURI.Path, err)
+			return fmt.Errorf("failed to walk workspace dir %q: %w", d.Name(), err)
 		}
 
 		// TODO(charlieegan3): make this configurable for things like .rq etc?
 		if d.IsDir() || !strings.HasSuffix(path, ".rego") {
 			return nil
 		}
 
-		_, err = updateCacheForURIFromDisk(l.cache, "file://"+path)
+		fileURI := uri.FromPath(l.clientIdentifier, path)
+
+		_, err = updateCacheForURIFromDisk(l.cache, fileURI, path)
 		if err != nil {
 			return fmt.Errorf("failed to update cache for uri %q: %w", path, err)
 		}
 
-		_, err = updateParse(l.cache, "file://"+path)
+		_, err = updateParse(l.cache, fileURI)
 		if err != nil {
 			return fmt.Errorf("failed to update parse: %w", err)
 		}
 
 		return nil
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to walk workspace dir %q: %w", folderURI.Path, err)
+		return nil, fmt.Errorf("failed to walk workspace dir %q: %w", workspaceRootPath, err)
 	}
 
 	// attempt to load the config as it is found on disk

internal/lsp/uri/uri.go

@@ -0,0 +1,45 @@
+package uri
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/styrainc/regal/internal/lsp/clients"
+)
+
+// FromPath converts a file path to a URI for a given client.
+// Since clients expect URIs to be in a specific format, this function
+// will convert the path to the appropriate format for the client.
+func FromPath(client clients.Identifier, path string) string {
+	path = strings.TrimPrefix(path, "file://")
+	path = strings.TrimPrefix(path, "/")
+
+	if client == clients.IdentifierVSCode {
+		// Convert Windows path separators to Unix separators
+		path = filepath.ToSlash(path)
+
+		// If the path is a Windows path, the colon after the drive letter needs to be
+		// percent-encoded.
+		if parts := strings.Split(path, ":"); len(parts) > 1 {
+			path = parts[0] + "%3A" + parts[1]
+		}
+	}
+
+	return "file://" + "/" + path
+}
+
+// ToPath converts a URI to a file path from a format for a given client.
+// Some clients represent URIs differently, and so this function exists to convert
+// client URIs into a standard file paths.
+func ToPath(client clients.Identifier, uri string) string {
+	path := strings.TrimPrefix(uri, "file://")
+
+	if client == clients.IdentifierVSCode {
+		if strings.Contains(path, ":") || strings.Contains(path, "%3A") {
+			path = strings.Replace(path, "%3A", ":", 1)
+			path = strings.TrimPrefix(path, "/")
+		}
+	}
+
+	return path
+}