feat(fstab): Add signature help support

server/handlers/fstab/handlers/signature_help.go

@@ -0,0 +1,85 @@
+package handlers
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/fstab/ast"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func GetEntrySignatureHelp(
+	entry *ast.FstabEntry,
+	cursor common.CursorPosition,
+) *protocol.SignatureHelp {
+	var index uint32
+
+	if entry == nil || entry.Fields.Spec == nil || entry.Fields.Spec.ContainsPosition(cursor) {
+		index = 0
+	} else if entry.Fields.MountPoint == nil && entry.Fields.MountPoint.ContainsPosition(cursor) {
+		index = 1
+	} else if entry.Fields.FilesystemType == nil && entry.Fields.FilesystemType.ContainsPosition(cursor) {
+		index = 2
+	} else if entry.Fields.Options == nil || entry.Fields.Options.ContainsPosition(cursor) {
+		index = 3
+	} else if entry.Fields.Freq == nil || entry.Fields.Freq.ContainsPosition(cursor) {
+		index = 4
+	} else {
+		index = 5
+	}
+
+	signature := uint32(0)
+
+	return &protocol.SignatureHelp{
+		ActiveSignature: &signature,
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "<spec> <mount point> <file system type> <options> <freq> <pass>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<spec>")),
+						},
+						Documentation: "The device or remote filesystem to mount",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<spec>")),
+							uint32(len("<spec> ") + len("<mount point>")),
+						},
+						Documentation: "The directory to mount the device or remote filesystem",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<spec> <mount point>")),
+							uint32(len("<spec> <mount point> ") + len("<file system type>")),
+						},
+						Documentation: "The type of filesystem",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<spec> <mount point> <file system type>")),
+							uint32(len("<spec> <mount point> <file system type> ") + len("<options>")),
+						},
+						Documentation: "Mount options",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<spec> <mount point> <file system type> <options>")),
+							uint32(len("<spec> <mount point> <file system type> <options> ") + len("<freq>")),
+						},
+						Documentation: "Used by dump(8) to determine which filesystems need to be dumped",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<spec> <mount point> <file system type> <options> <freq>")),
+							uint32(len("<spec> <mount point> <file system type> <options> <freq> ") + len("<pass>")),
+						},
+						Documentation: "Used by fsck(8) to determine the order in which filesystem checks are done at boot time",
+					},
+				},
+			},
+		},
+	}
+}

server/handlers/fstab/lsp/text-document-signature-help.go

@@ -0,0 +1,31 @@
+package lsp
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/fstab/ast"
+	"config-lsp/handlers/fstab/handlers"
+	fstab "config-lsp/handlers/fstab/shared"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) {
+	document := fstab.DocumentParserMap[params.TextDocument.URI]
+
+	line := uint32(params.Position.Line)
+	cursor := common.LSPCharacterAsCursorPosition(params.Position.Character)
+
+	if _, found := document.Config.CommentLines[line]; found {
+		// Comment
+		return nil, nil
+	}
+
+	entry, found := document.Config.Entries.Get(line)
+
+	if !found {
+		return handlers.GetEntrySignatureHelp(nil, cursor), nil
+	} else {
+		return handlers.GetEntrySignatureHelp(entry.(*ast.FstabEntry), cursor), nil
+	}
+}

server/root-handler/text-document-signature-help.go

@@ -2,6 +2,7 @@ package roothandler
 
 import (
 	aliases "config-lsp/handlers/aliases/lsp"
+	fstab "config-lsp/handlers/fstab/lsp"
 	hosts "config-lsp/handlers/hosts/lsp"
 	sshconfig "config-lsp/handlers/ssh_config/lsp"
 	sshdconfig "config-lsp/handlers/sshd_config/lsp"
@@ -31,7 +32,7 @@ func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.Signature
 	case LanguageSSHConfig:
 		return sshconfig.TextDocumentSignatureHelp(context, params)
 	case LanguageFstab:
-		return nil, nil
+		return fstab.TextDocumentSignatureHelp(context, params)
 	case LanguageWireguard:
 		return nil, nil
 	case LanguageAliases: