Merge pull request #9 from OriginalDecode/fix_exception_invalid_language

Fixed an exception that crashed the extension due to invalid language.

Author: georgewfraser

src/extension.ts

@@ -2,7 +2,7 @@ import * as VS from 'vscode'
 import * as Parser from 'tree-sitter'
 
 // Be sure to declare the language in package.json and include a minimalist grammar.
-const languages: {[id: string]: {parser: Parser, color: ColorFunction}} = {
+const languages: { [id: string]: { parser: Parser, color: ColorFunction } } = {
 	'go': createParser('tree-sitter-go', colorGo),
 	'typescript': createParser('tree-sitter-typescript', colorTypescript),
 	'cpp': createParser('tree-sitter-cpp', colorCpp),
@@ -28,7 +28,7 @@ function colorGo(x: Parser.SyntaxNode, editor: VS.TextEditor) {
 	}
 	scan(x)
 
-	return {types, fields, functions}
+	return { types, fields, functions }
 }
 
 function colorTypescript(x: Parser.SyntaxNode, editor: VS.TextEditor) {
@@ -50,7 +50,7 @@ function colorTypescript(x: Parser.SyntaxNode, editor: VS.TextEditor) {
 	}
 	scan(x)
 
-	return {types, fields, functions}
+	return { types, fields, functions }
 }
 
 function colorRust(x: Parser.SyntaxNode, editor: VS.TextEditor) {
@@ -76,7 +76,7 @@ function colorRust(x: Parser.SyntaxNode, editor: VS.TextEditor) {
 	}
 	scan(x)
 
-	return {types, fields, functions}
+	return { types, fields, functions }
 }
 
 function colorCpp(x: Parser.SyntaxNode, editor: VS.TextEditor) {
@@ -100,12 +100,12 @@ function colorCpp(x: Parser.SyntaxNode, editor: VS.TextEditor) {
 	}
 	scan(x)
 
-	return {types, fields, functions}
+	return { types, fields, functions }
 }
 
 function isVisible(x: Parser.SyntaxNode, editor: VS.TextEditor) {
 	for (let visible of editor.visibleRanges) {
-		const overlap = x.startPosition.row <= visible.end.line+1 && visible.start.line-1 <= x.endPosition.row
+		const overlap = x.startPosition.row <= visible.end.line + 1 && visible.start.line - 1 <= x.endPosition.row
 		if (overlap) return true
 	}
 	return false
@@ -115,33 +115,39 @@ function range(x: Parser.SyntaxNode): VS.Range {
 	return new VS.Range(x.startPosition.row, x.startPosition.column, x.endPosition.row, x.endPosition.column)
 }
 
-type ColorFunction = (x: Parser.SyntaxNode, editor: VS.TextEditor) => {types: VS.Range[], fields: VS.Range[], functions: VS.Range[]}
+type ColorFunction = (x: Parser.SyntaxNode, editor: VS.TextEditor) => { types: VS.Range[], fields: VS.Range[], functions: VS.Range[] }
 
-function createParser(module: string, color: ColorFunction): {parser: Parser, color: ColorFunction} {
+function createParser(module: string, color: ColorFunction): { parser: Parser, color: ColorFunction } {
 	const lang = require(module)
 	const parser = new Parser()
 	parser.setLanguage(lang)
-	return {parser, color}
+	return { parser, color }
 }
 
 // Called when the extension is first activated by user opening a file with the appropriate language
 export function activate(context: VS.ExtensionContext) {
 	console.log("Activating tree-sitter...")
 	// Parse of all visible documents
-	const trees: {[uri: string]: Parser.Tree} = {}
+	const trees: { [uri: string]: Parser.Tree } = {}
 	function open(editor: VS.TextEditor) {
-		const {parser} = languages[editor.document.languageId]
-		if (parser != null) {
-			const t = parser.parse(editor.document.getText()) // TODO don't use getText, use Parser.Input
-			trees[editor.document.uri.toString()] = t
-			colorUri(editor.document.uri)
+		const languageSpec = languages[editor.document.languageId]
+		if (languageSpec != null) {
+			const { parser } = languageSpec
+			if (parser != null) {
+				const t = parser.parse(editor.document.getText()) // TODO don't use getText, use Parser.Input
+				trees[editor.document.uri.toString()] = t
+				colorUri(editor.document.uri)
+			}
 		}
 	}
 	function edit(edit: VS.TextDocumentChangeEvent) {
-		const {parser} = languages[edit.document.languageId]
-		if (parser != null) {
-			updateTree(parser, edit)
-			colorUri(edit.document.uri)
+		const languageSpec = languages[edit.document.languageId]
+		if (languageSpec != null) {
+			const { parser } = languageSpec
+			if (parser != null) {
+				updateTree(parser, edit)
+				colorUri(edit.document.uri)
+			}
 		}
 	}
 	function updateTree(parser: Parser, edit: VS.TextDocumentChangeEvent) {
@@ -156,7 +162,7 @@ export function activate(context: VS.ExtensionContext) {
 		const startPosition = asPoint(startPos)
 		const oldEndPosition = asPoint(oldEndPos)
 		const newEndPosition = asPoint(newEndPos)
-		const delta = {startIndex, oldEndIndex, newEndIndex, startPosition, oldEndPosition, newEndPosition}
+		const delta = { startIndex, oldEndIndex, newEndIndex, startPosition, oldEndPosition, newEndPosition }
 		// console.log(edit.document.uri.toString(), delta)
 		old.edit(delta)
 		const t = parser.parse(edit.document.getText(), old) // TODO don't use getText, use Parser.Input
@@ -172,7 +178,7 @@ export function activate(context: VS.ExtensionContext) {
 		return edit.rangeOffset + edit.text.length
 	}
 	function asPoint(pos: VS.Position): Parser.Point {
-		return {row: pos.line, column: pos.character}
+		return { row: pos.line, column: pos.character }
 	}
 	function close(doc: VS.TextDocument) {
 		if (doc.languageId == 'go') {
@@ -181,13 +187,13 @@ export function activate(context: VS.ExtensionContext) {
 	}
 	// Apply themeable colors
 	const typeStyle = VS.window.createTextEditorDecorationType({
-        color: new VS.ThemeColor('treeSitter.type')
+		color: new VS.ThemeColor('treeSitter.type')
 	})
 	const fieldStyle = VS.window.createTextEditorDecorationType({
-        color: new VS.ThemeColor('treeSitter.field')
+		color: new VS.ThemeColor('treeSitter.field')
 	})
 	const functionStyle = VS.window.createTextEditorDecorationType({
-        color: new VS.ThemeColor('treeSitter.function')
+		color: new VS.ThemeColor('treeSitter.function')
 	})
 	function colorUri(uri: VS.Uri) {
 		for (let editor of VS.window.visibleTextEditors) {
@@ -199,12 +205,15 @@ export function activate(context: VS.ExtensionContext) {
 	function colorEditor(editor: VS.TextEditor) {
 		const t = trees[editor.document.uri.toString()]
 		if (t == null) return;
-		const {color} = languages[editor.document.languageId]
-		if (color == null) return;
-		const {types, fields, functions} = color(t.rootNode, editor)
-		editor.setDecorations(typeStyle, types)
-		editor.setDecorations(fieldStyle, fields)
-		editor.setDecorations(functionStyle, functions)
+		const languageSpec = languages[editor.document.languageId]
+		if (languageSpec != null) {
+			const { color } = languageSpec
+			if (color == null) return;
+			const { types, fields, functions } = color(t.rootNode, editor)
+			editor.setDecorations(typeStyle, types)
+			editor.setDecorations(fieldStyle, fields)
+			editor.setDecorations(functionStyle, functions)
+		}
 		// console.log(t.rootNode.toString())
 	}
 	VS.window.visibleTextEditors.forEach(open)
@@ -215,4 +224,4 @@ export function activate(context: VS.ExtensionContext) {
 }
 
 // this method is called when your extension is deactivated
-export function deactivate() {}
+export function deactivate() { }