feat: Improve root handler; Improve language detection; Bugfixes

common/errors.go

@@ -1,10 +1,21 @@
 package common
 
+import (
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
 type LSPError struct {
 	Range LocationRange
 	Err   error
 }
 
+func (l LSPError) ToDiagnostic() protocol.Diagnostic {
+	return protocol.Diagnostic{
+		Range:   l.Range.ToLSPRange(),
+		Message: l.Err.Error(),
+	}
+}
+
 type SyntaxError struct {
 	Message string
 }

common/location.go

@@ -1,5 +1,7 @@
 package common
 
+import protocol "github.com/tliron/glsp/protocol_3_16"
+
 type Location struct {
 	Line      uint32
 	Character uint32
@@ -10,11 +12,37 @@ type LocationRange struct {
 	End   Location
 }
 
+func (l LocationRange) ToLSPRange() protocol.Range {
+	return protocol.Range{
+		Start: protocol.Position{
+			Line:      l.Start.Line,
+			Character: l.Start.Character,
+		},
+		End: protocol.Position{
+			Line:      l.End.Line,
+			Character: l.End.Character,
+		},
+	}
+}
+
 func (l *LocationRange) ChangeBothLines(newLine uint32) {
 	l.Start.Line = newLine
 	l.End.Line = newLine
 }
 
+func CreateFullLineRange(line uint32) LocationRange {
+	return LocationRange{
+		Start: Location{
+			Line:      line,
+			Character: 0,
+		},
+		End: Location{
+			Line:      line,
+			Character: 999999,
+		},
+	}
+}
+
 func CreateSingleCharRange(line uint32, character uint32) LocationRange {
 	return LocationRange{
 		Start: Location{

handlers/hosts/handlers/analyzer/analyzer.go

@@ -1 +1,32 @@
 package analyzer
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/hosts/tree"
+	"config-lsp/utils"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func Analyze(parser tree.HostsParser) []protocol.Diagnostic {
+	errors := analyzeEntriesAreValid(parser)
+
+	if len(errors) > 0 {
+		return utils.Map(
+			errors,
+			func(err common.LSPError) protocol.Diagnostic {
+				return err.ToDiagnostic()
+			},
+		)
+	}
+
+	errors = append(errors, analyzeDoubleIPs(parser)...)
+	errors = append(errors, analyzeDoubleHostNames(parser)...)
+
+	return utils.Map(
+		errors,
+		func(err common.LSPError) protocol.Diagnostic {
+			return err.ToDiagnostic()
+		},
+	)
+}

handlers/hosts/handlers/analyzer/double_ips_test.go

@@ -52,11 +52,11 @@ func TestWorksWithDoubleIPs(
 		t.Errorf("Expected 1 error, but got %v", len(errors))
 	}
 
-	if !(errors[0].Range.Start.Line == 3) {
+	if !(errors[0].Range.Start.Line == 2) {
 		t.Errorf("Expected error on line 3, but got %v", errors[0].Range.Start.Line)
 	}
 
-	if !(errors[0].Err.(DuplicateIPDeclaration).AlreadyFoundAt == 1) {
+	if !(errors[0].Err.(DuplicateIPDeclaration).AlreadyFoundAt == 0) {
 		t.Errorf("Expected error on line 1, but got %v", errors[0].Err.(DuplicateIPDeclaration).AlreadyFoundAt)
 	}
 }

handlers/hosts/handlers/analyzer/resolver.go

@@ -39,7 +39,7 @@ type hostnameEntry struct {
 	HostName string
 }
 
-func CreateResolverFromParser(p tree.HostsParser) (Resolver, []common.LSPError) {
+func createResolverFromParser(p tree.HostsParser) (Resolver, []common.LSPError) {
 	errors := make([]common.LSPError, 0)
 	resolver := Resolver{
 		Entries: make(map[string]ResolverEntry),
@@ -91,3 +91,9 @@ func CreateResolverFromParser(p tree.HostsParser) (Resolver, []common.LSPError)
 
 	return resolver, errors
 }
+
+func analyzeDoubleHostNames(p tree.HostsParser) []common.LSPError {
+	_, errors := createResolverFromParser(p)
+
+	return errors
+}

handlers/hosts/handlers/analyzer/resolver_test.go

@@ -21,7 +21,7 @@ func TestResolverEntriesWorksWithNonOverlapping(
 		t.Fatalf("PARER FAILED! Expected no errors, but got %v", errors)
 	}
 
-	resolver, errors := CreateResolverFromParser(parser)
+	resolver, errors := createResolverFromParser(parser)
 
 	if len(errors) != 0 {
 		t.Errorf("Expected no errors, but got %v", errors)
@@ -63,7 +63,7 @@ func TestResolverEntriesWithSimpleOverlapping(
 		t.Fatalf("PARER FAILED! Expected no errors, but got %v", errors)
 	}
 
-	resolver, errors := CreateResolverFromParser(parser)
+	resolver, errors := createResolverFromParser(parser)
 
 	if !(len(errors) == 1) {
 		t.Errorf("Expected 1 error, but got %v", len(errors))
@@ -93,7 +93,7 @@ func TestResolverEntriesWithComplexOverlapping(
 		t.Fatalf("PARER FAILED! Expected no errors, but got %v", errors)
 	}
 
-	resolver, errors := CreateResolverFromParser(parser)
+	resolver, errors := createResolverFromParser(parser)
 
 	if !(len(errors) == 1) {
 		t.Errorf("Expected 1 error, but got %v", len(errors))

handlers/hosts/handlers/analyzer/values.go

@@ -0,0 +1,33 @@
+package analyzer
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/hosts/tree"
+	"errors"
+)
+
+func analyzeEntriesAreValid(
+	parser tree.HostsParser,
+) []common.LSPError {
+	err := make([]common.LSPError, 0)
+
+	for lineNumber, entry := range parser.Tree.Entries {
+		if entry.IPAddress == nil {
+			err = append(err, common.LSPError{
+				Range: common.CreateFullLineRange(lineNumber),
+				Err:   errors.New("IP Address is required"),
+			})
+			continue
+		}
+
+		if entry.Hostname == nil {
+			err = append(err, common.LSPError{
+				Range: common.CreateFullLineRange(lineNumber),
+				Err:   errors.New("Hostname is required"),
+			})
+			continue
+		}
+	}
+
+	return err
+}

handlers/hosts/lsp/shared.go

@@ -0,0 +1,9 @@
+package lsp
+
+import (
+	"config-lsp/handlers/hosts/tree"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+var documentParserMap = map[protocol.DocumentUri]*tree.HostsParser{}

handlers/hosts/lsp/text-document-completion.go

@@ -0,0 +1,12 @@
+package lsp
+
+import (
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentCompletion(context *glsp.Context, params *protocol.CompletionParams) (any, error) {
+	// p := documentParserMap[params.TextDocument.URI]
+
+	return nil, nil
+}

handlers/hosts/lsp/text-document-did-change.go

@@ -0,0 +1,41 @@
+package lsp
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/hosts/handlers/analyzer"
+	"config-lsp/utils"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentDidChange(
+	context *glsp.Context,
+	params *protocol.DidChangeTextDocumentParams,
+) error {
+	content := params.ContentChanges[0].(protocol.TextDocumentContentChangeEventWhole).Text
+	common.ClearDiagnostics(context, params.TextDocument.URI)
+
+	parser := documentParserMap[params.TextDocument.URI]
+	parser.Clear()
+
+	diagnostics := make([]protocol.Diagnostic, 0)
+	errors := parser.Parse(content)
+
+	if len(errors) > 0 {
+		diagnostics = append(diagnostics, utils.Map(
+			errors,
+			func(err common.LSPError) protocol.Diagnostic {
+				return err.ToDiagnostic()
+			},
+		)...)
+	}
+
+	diagnostics = append(diagnostics, analyzer.Analyze(*parser)...)
+
+	if len(diagnostics) > 0 {
+		common.SendDiagnostics(context, params.TextDocument.URI, diagnostics)
+	}
+
+	return nil
+}

handlers/hosts/lsp/text-document-did-close.go

@@ -0,0 +1,12 @@
+package lsp
+
+import (
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentDidClose(context *glsp.Context, params *protocol.DidCloseTextDocumentParams) error {
+	delete(documentParserMap, params.TextDocument.URI)
+
+	return nil
+}

handlers/hosts/lsp/text-document-did-open.go

@@ -0,0 +1,41 @@
+package lsp
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/hosts/handlers/analyzer"
+	"config-lsp/handlers/hosts/tree"
+	"config-lsp/utils"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentDidOpen(
+	context *glsp.Context,
+	params *protocol.DidOpenTextDocumentParams,
+) error {
+	common.ClearDiagnostics(context, params.TextDocument.URI)
+
+	parser := tree.CreateNewHostsParser()
+	documentParserMap[params.TextDocument.URI] = &parser
+
+	errors := parser.Parse(params.TextDocument.Text)
+
+	diagnostics := utils.Map(
+		errors,
+		func(err common.LSPError) protocol.Diagnostic {
+			return err.ToDiagnostic()
+		},
+	)
+
+	diagnostics = append(
+		diagnostics,
+		analyzer.Analyze(parser)...,
+	)
+
+	if len(diagnostics) > 0 {
+		common.SendDiagnostics(context, params.TextDocument.URI, diagnostics)
+	}
+
+	return nil
+}

handlers/hosts/tree/handler.go

@@ -3,8 +3,8 @@ package tree
 import (
 	"config-lsp/common"
 	"config-lsp/handlers/hosts/parser"
+	"config-lsp/utils"
 	"regexp"
-	"strings"
 
 	"github.com/antlr4-go/antlr/v4"
 )
@@ -51,10 +51,10 @@ func (p *HostsParser) parseStatement(
 
 func (p *HostsParser) Parse(input string) []common.LSPError {
 	errors := make([]common.LSPError, 0)
-	lines := strings.Split(input, "\n")
+	lines := utils.SplitIntoLines(input)
 
 	for rawLineNumber, line := range lines {
-		lineNumber := uint32(rawLineNumber + 1)
+		lineNumber := uint32(rawLineNumber)
 
 		if commentPattern.MatchString(line) {
 			p.CommentLines[lineNumber] = struct{}{}

handlers/hosts/tree/handler_test.go

@@ -24,44 +24,44 @@ func TestValidSimpleExampleWorks(
 		t.Errorf("Expected 1 entry, but got %v", len(parser.Tree.Entries))
 	}
 
-	if parser.Tree.Entries[1].IPAddress == nil {
+	if parser.Tree.Entries[0].IPAddress == nil {
 		t.Errorf("Expected IP address to be present, but got nil")
 	}
 
-	if !(parser.Tree.Entries[1].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
+	if !(parser.Tree.Entries[0].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
-		t.Errorf("Expected IP address to be 1.2.3.4, but got %v", parser.Tree.Entries[1].IPAddress.Value)
+		t.Errorf("Expected IP address to be 1.2.3.4, but got %v", parser.Tree.Entries[0].IPAddress.Value)
 	}
 
-	if !(parser.Tree.Entries[1].Hostname.Value == "hello.com") {
+	if !(parser.Tree.Entries[0].Hostname.Value == "hello.com") {
-		t.Errorf("Expected hostname to be hello.com, but got %v", parser.Tree.Entries[1].Hostname.Value)
+		t.Errorf("Expected hostname to be hello.com, but got %v", parser.Tree.Entries[0].Hostname.Value)
 	}
 
-	if !(parser.Tree.Entries[1].Aliases == nil) {
+	if !(parser.Tree.Entries[0].Aliases == nil) {
-		t.Errorf("Expected no aliases, but got %v", parser.Tree.Entries[1].Aliases)
+		t.Errorf("Expected no aliases, but got %v", parser.Tree.Entries[0].Aliases)
 	}
 
-	if !(parser.Tree.Entries[1].Location.Start.Line == 1) {
+	if !(parser.Tree.Entries[0].Location.Start.Line == 0) {
-		t.Errorf("Expected line to be 1, but got %v", parser.Tree.Entries[1].Location.Start.Line)
+		t.Errorf("Expected line to be 1, but got %v", parser.Tree.Entries[0].Location.Start.Line)
 	}
 
-	if !(parser.Tree.Entries[1].Location.Start.Character == 0) {
+	if !(parser.Tree.Entries[0].Location.Start.Character == 0) {
-		t.Errorf("Expected start to be 0, but got %v", parser.Tree.Entries[1].Location.Start)
+		t.Errorf("Expected start to be 0, but got %v", parser.Tree.Entries[0].Location.Start)
 	}
 
-	if !(parser.Tree.Entries[1].Location.End.Character == 16) {
+	if !(parser.Tree.Entries[0].Location.End.Character == 16) {
-		t.Errorf("Expected end to be 16, but got %v", parser.Tree.Entries[1].Location.End.Character)
+		t.Errorf("Expected end to be 16, but got %v", parser.Tree.Entries[0].Location.End.Character)
 	}
 
-	if !(parser.Tree.Entries[1].IPAddress.Location.Start.Line == 1) {
+	if !(parser.Tree.Entries[0].IPAddress.Location.Start.Line == 0) {
-		t.Errorf("Expected IP address line to be 1, but got %v", parser.Tree.Entries[1].IPAddress.Location.Start.Line)
+		t.Errorf("Expected IP address line to be 1, but got %v", parser.Tree.Entries[0].IPAddress.Location.Start.Line)
 	}
 
-	if !(parser.Tree.Entries[1].IPAddress.Location.Start.Character == 0) {
+	if !(parser.Tree.Entries[0].IPAddress.Location.Start.Character == 0) {
-		t.Errorf("Expected IP address start to be 0, but got %v", parser.Tree.Entries[1].IPAddress.Location.Start.Character)
+		t.Errorf("Expected IP address start to be 0, but got %v", parser.Tree.Entries[0].IPAddress.Location.Start.Character)
 	}
 
-	if !(parser.Tree.Entries[1].IPAddress.Location.End.Character == 6) {
+	if !(parser.Tree.Entries[0].IPAddress.Location.End.Character == 6) {
-		t.Errorf("Expected IP address end to be 6, but got %v", parser.Tree.Entries[1].IPAddress.Location.End.Character)
+		t.Errorf("Expected IP address end to be 6, but got %v", parser.Tree.Entries[0].IPAddress.Location.End.Character)
 	}
 
 	if !(len(parser.CommentLines) == 0) {
@@ -91,11 +91,11 @@ func TestValidComplexExampleWorks(
 		t.Errorf("Expected 3 entries, but got %v", len(parser.Tree.Entries))
 	}
 
-	if parser.Tree.Entries[3].IPAddress == nil {
+	if parser.Tree.Entries[2].IPAddress == nil {
 		t.Errorf("Expected IP address to be present, but got nil")
 	}
 
-	if !(parser.Tree.Entries[3].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
+	if !(parser.Tree.Entries[2].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
 		t.Errorf("Expected IP address to be 1.2.3.4, but got %v", parser.Tree.Entries[2].IPAddress.Value)
 	}
 
@@ -103,7 +103,7 @@ func TestValidComplexExampleWorks(
 		t.Errorf("Expected 1 comment line, but got %v", len(parser.CommentLines))
 	}
 
-	if !(utils.KeyExists(parser.CommentLines, 2)) {
+	if !(utils.KeyExists(parser.CommentLines, 1)) {
 		t.Errorf("Expected comment line 2 to exist, but it does not")
 	}
 }
@@ -130,15 +130,15 @@ func TestInvalidExampleWorks(
 		t.Errorf("Expected no comment lines, but got %v", len(parser.CommentLines))
 	}
 
-	if !(parser.Tree.Entries[1].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
+	if !(parser.Tree.Entries[0].IPAddress.Value.String() == net.ParseIP("1.2.3.4").String()) {
-		t.Errorf("Expected IP address to be nil, but got %v", parser.Tree.Entries[1].IPAddress)
+		t.Errorf("Expected IP address to be nil, but got %v", parser.Tree.Entries[0].IPAddress)
 	}
 
-	if !(parser.Tree.Entries[1].Hostname == nil) {
+	if !(parser.Tree.Entries[0].Hostname == nil) {
-		t.Errorf("Expected hostname to be nil, but got %v", parser.Tree.Entries[1].Hostname)
+		t.Errorf("Expected hostname to be nil, but got %v", parser.Tree.Entries[0].Hostname)
 	}
 
-	if !(parser.Tree.Entries[1].Aliases == nil) {
+	if !(parser.Tree.Entries[0].Aliases == nil) {
-		t.Errorf("Expected aliases to be nil, but got %v", parser.Tree.Entries[1].Aliases)
+		t.Errorf("Expected aliases to be nil, but got %v", parser.Tree.Entries[0].Aliases)
 	}
 }

root-handler/lsp-utils.go

@@ -16,12 +16,14 @@ const (
 	LanguageSSHDConfig SupportedLanguage = "sshd_config"
 	LanguageFstab      SupportedLanguage = "fstab"
 	LanguageWireguard  SupportedLanguage = "languagewireguard"
+	LanguageHosts      SupportedLanguage = "hosts"
 )
 
 var AllSupportedLanguages = []string{
 	string(LanguageSSHDConfig),
 	string(LanguageFstab),
 	string(LanguageWireguard),
+	string(LanguageHosts),
 }
 
 type FatalFileNotReadableError struct {
@@ -59,11 +61,19 @@ var valueToLanguageMap = map[string]SupportedLanguage{
 	"wireguard":         LanguageWireguard,
 	"wg":                LanguageWireguard,
 	"languagewireguard": LanguageWireguard,
+	"host":              LanguageHosts,
+	"hosts":             LanguageHosts,
+	"etc/hosts":         LanguageHosts,
 }
 
-var typeOverwriteRegex = regexp.MustCompile(`^#\?\s*lsp\.language\s*=\s*(\w+)\s*$`)
+var typeOverwriteRegex = regexp.MustCompile(`#\?\s*lsp\.language\s*=\s*(\w+)\s*`)
 var wireguardPattern = regexp.MustCompile(`/wg\d+\.conf$`)
 
+var undetectableError = common.ParseError{
+	Line: 0,
+	Err:  LanguageUndetectableError{},
+}
+
 func DetectLanguage(
 	content string,
 	advertisedLanguage string,
@@ -99,14 +109,13 @@ func DetectLanguage(
 		return LanguageSSHDConfig, nil
 	case "file:///etc/fstab":
 		return LanguageFstab, nil
+	case "file:///etc/hosts":
+		return LanguageHosts, nil
 	}
 
 	if strings.HasPrefix(uri, "file:///etc/wireguard/") || wireguardPattern.MatchString(uri) {
 		return LanguageWireguard, nil
 	}
 
-	return "", common.ParseError{
+	return "", undetectableError
-		Line: 0,
-		Err:  LanguageUndetectableError{},
-	}
 }

root-handler/singleton.go

@@ -20,8 +20,14 @@ func (h *RootHandler) AddDocument(uri protocol.DocumentUri, language SupportedLa
 	h.languageMap[uri] = language
 }
 
-func (h *RootHandler) GetLanguageForDocument(uri protocol.DocumentUri) SupportedLanguage {
+func (h *RootHandler) GetLanguageForDocument(uri protocol.DocumentUri) *SupportedLanguage {
-	return h.languageMap[uri]
+	language, found := h.languageMap[uri]
+
+	if !found {
+		return nil
+	}
+
+	return &language
 }
 
 func (h *RootHandler) RemoveDocument(uri protocol.DocumentUri) {

root-handler/text-document-code-action.go

@@ -9,14 +9,26 @@ import (
 func TextDocumentCodeAction(context *glsp.Context, params *protocol.CodeActionParams) (any, error) {
 	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
 
-	switch language {
+	if language == nil {
+		showParseError(
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return nil, undetectableError.Err
+	}
+
+	switch *language {
 	case LanguageFstab:
-		return nil, nil
+		fallthrough
+	case LanguageHosts:
+		fallthrough
 	case LanguageSSHDConfig:
 		return nil, nil
 	case LanguageWireguard:
 		return wireguard.TextDocumentCodeAction(context, params)
 	}
 
-	panic("root-handler/TextDocumentCompletion: unexpected language" + language)
+	panic("root-handler/TextDocumentCompletion: unexpected language" + *language)
 }

root-handler/text-document-completion.go

@@ -2,6 +2,7 @@ package roothandler
 
 import (
 	"config-lsp/handlers/fstab"
+	hosts "config-lsp/handlers/hosts/lsp"
 	wireguard "config-lsp/handlers/wireguard/lsp"
 
 	"github.com/tliron/glsp"
@@ -11,14 +12,26 @@ import (
 func TextDocumentCompletion(context *glsp.Context, params *protocol.CompletionParams) (any, error) {
 	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
 
-	switch language {
+	if language == nil {
+		showParseError(
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return nil, undetectableError.Err
+	}
+
+	switch *language {
 	case LanguageFstab:
 		return fstab.TextDocumentCompletion(context, params)
 	case LanguageSSHDConfig:
 		return nil, nil
 	case LanguageWireguard:
 		return wireguard.TextDocumentCompletion(context, params)
+	case LanguageHosts:
+		return hosts.TextDocumentCompletion(context, params)
 	}
 
-	panic("root-handler/TextDocumentCompletion: unexpected language" + language)
+	panic("root-handler/TextDocumentCompletion: unexpected language" + *language)
 }

root-handler/text-document-did-change.go

@@ -2,6 +2,7 @@ package roothandler
 
 import (
 	"config-lsp/handlers/fstab"
+	hosts "config-lsp/handlers/hosts/lsp"
 	wireguard "config-lsp/handlers/wireguard/lsp"
 
 	"github.com/tliron/glsp"
@@ -11,14 +12,52 @@ import (
 func TextDocumentDidChange(context *glsp.Context, params *protocol.DidChangeTextDocumentParams) error {
 	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
 
-	switch language {
+	if language == nil {
+		content := params.ContentChanges[0].(protocol.TextDocumentContentChangeEventWhole).Text
+		newLanguage, err := initFile(
+			context,
+			content,
+			params.TextDocument.URI,
+			"",
+		)
+
+		if err != nil {
+			return err
+		}
+
+		language = newLanguage
+
+		params := &protocol.DidOpenTextDocumentParams{
+			TextDocument: protocol.TextDocumentItem{
+				URI:        params.TextDocument.URI,
+				Text:       content,
+				Version:    params.TextDocument.Version,
+				LanguageID: string(*language),
+			},
+		}
+
+		switch *language {
+		case LanguageFstab:
+			return fstab.TextDocumentDidOpen(context, params)
+		case LanguageSSHDConfig:
+			break
+		case LanguageWireguard:
+			return wireguard.TextDocumentDidOpen(context, params)
+		case LanguageHosts:
+			return hosts.TextDocumentDidOpen(context, params)
+		}
+	}
+
+	switch *language {
 	case LanguageFstab:
 		return fstab.TextDocumentDidChange(context, params)
 	case LanguageSSHDConfig:
 		return nil
 	case LanguageWireguard:
 		return wireguard.TextDocumentDidChange(context, params)
+	case LanguageHosts:
+		return hosts.TextDocumentDidChange(context, params)
 	}
 
-	panic("root-handler/TextDocumentDidChange: unexpected language" + language)
+	panic("root-handler/TextDocumentDidChange: unexpected language" + *language)
 }

root-handler/text-document-did-close.go

@@ -1,6 +1,7 @@
 package roothandler
 
 import (
+	hosts "config-lsp/handlers/hosts/lsp"
 	wireguard "config-lsp/handlers/wireguard/lsp"
 
 	"github.com/tliron/glsp"
@@ -10,14 +11,26 @@ import (
 func TextDocumentDidClose(context *glsp.Context, params *protocol.DidCloseTextDocumentParams) error {
 	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
 
+	if language == nil {
+		showParseError(
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return undetectableError.Err
+	}
+
 	delete(openedFiles, params.TextDocument.URI)
 	rootHandler.RemoveDocument(params.TextDocument.URI)
 
-	switch language {
+	switch *language {
 	case LanguageFstab:
 	case LanguageSSHDConfig:
 	case LanguageWireguard:
 		return wireguard.TextDocumentDidClose(context, params)
+	case LanguageHosts:
+		return hosts.TextDocumentDidClose(context, params)
 	default:
 	}
 

root-handler/text-document-did-open.go

@@ -3,6 +3,7 @@ package roothandler
 import (
 	"config-lsp/common"
 	fstab "config-lsp/handlers/fstab"
+	hosts "config-lsp/handlers/hosts/lsp"
 	wireguard "config-lsp/handlers/wireguard/lsp"
 	"fmt"
 
@@ -15,31 +16,26 @@ func TextDocumentDidOpen(context *glsp.Context, params *protocol.DidOpenTextDocu
 
 	// Find the file type
 	content := params.TextDocument.Text
-	language, err := DetectLanguage(content, params.TextDocument.LanguageID, params.TextDocument.URI)
+	language, err := initFile(
-
-	if err != nil {
-		parseError := err.(common.ParseError)
-		showParseError(
 		context,
+		content,
 		params.TextDocument.URI,
-			parseError,
+		params.TextDocument.LanguageID,
 	)
 
-		return parseError.Err
+	if err != nil {
+		return err
 	}
 
-	openedFiles[params.TextDocument.URI] = struct{}{}
+	switch *language {
-
-	// Everything okay, now we can handle the file
-	rootHandler.AddDocument(params.TextDocument.URI, language)
-
-	switch language {
 	case LanguageFstab:
 		return fstab.TextDocumentDidOpen(context, params)
 	case LanguageSSHDConfig:
 		break
 	case LanguageWireguard:
 		return wireguard.TextDocumentDidOpen(context, params)
+	case LanguageHosts:
+		return hosts.TextDocumentDidOpen(context, params)
 	}
 
 	panic(fmt.Sprintf("unexpected roothandler.SupportedLanguage: %#v", language))
@@ -73,3 +69,30 @@ func showParseError(
 		},
 	)
 }
+
+func initFile(
+	context *glsp.Context,
+	content string,
+	uri protocol.DocumentUri,
+	advertisedLanguage string,
+) (*SupportedLanguage, error) {
+	language, err := DetectLanguage(content, advertisedLanguage, uri)
+
+	if err != nil {
+		parseError := err.(common.ParseError)
+		showParseError(
+			context,
+			uri,
+			parseError,
+		)
+
+		return nil, parseError.Err
+	}
+
+	openedFiles[uri] = struct{}{}
+
+	// Everything okay, now we can handle the file
+	rootHandler.AddDocument(uri, language)
+
+	return &language, nil
+}

root-handler/text-document-hover.go

@@ -11,14 +11,26 @@ import (
 func TextDocumentHover(context *glsp.Context, params *protocol.HoverParams) (*protocol.Hover, error) {
 	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
 
-	switch language {
+	if language == nil {
-	case LanguageFstab:
+		showParseError(
-		return fstab.TextDocumentHover(context, params)
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return nil, undetectableError.Err
+	}
+
+	switch *language {
+	case LanguageHosts:
+		fallthrough
 	case LanguageSSHDConfig:
 		return nil, nil
+	case LanguageFstab:
+		return fstab.TextDocumentHover(context, params)
 	case LanguageWireguard:
 		return wireguard.TextDocumentHover(context, params)
 	}
 
-	panic("root-handler/TextDocumentHover: unexpected language" + language)
+	panic("root-handler/TextDocumentHover: unexpected language" + *language)
 }

utils/strings.go

@@ -15,3 +15,7 @@ func GetTrimIndex(s string) []int {
 
 	return indexes[2:4]
 }
+
+func SplitIntoLines(s string) []string {
+	return regexp.MustCompile("\r?\n").Split(s, -1)
+}