#22799 Enhance json edit to support removing elements from array

src/vs/base/common/jsonEdit.ts

@@ -81,6 +81,7 @@ export function setProperty(text: string, path: JSONPath, value: any, formatting
 	} else if (parent.type === 'array' && typeof lastSegment === 'number') {
 		let insertIndex = lastSegment;
 		if (insertIndex === -1) {
+			// Insert
 			let newProperty = `${JSON.stringify(value)}`;
 			let edit: Edit;
 			if (parent.children.length === 0) {
@@ -91,7 +92,26 @@ export function setProperty(text: string, path: JSONPath, value: any, formatting
 			}
 			return withFormatting(text, edit, formattingOptions);
 		} else {
-			throw new Error('Array modification not supported yet');
+			if (value === void 0 && parent.children.length >= 0) {
+				//Removal
+				let removalIndex = lastSegment;
+				let toRemove = parent.children[removalIndex];
+				let edit: Edit;
+				if (parent.children.length === 1) {
+					// only item
+					edit = { offset: parent.offset + 1, length: parent.length - 2, content: '' };
+				} else if (parent.children.length - 1 === removalIndex) {
+					// last item
+					let previous = parent.children[removalIndex - 1];
+					let offset = previous.offset + previous.length;
+					edit = { offset, length: parent.length - 2 - offset, content: '' };
+				} else {
+					edit = { offset: toRemove.offset, length: parent.children[removalIndex + 1].offset - toRemove.offset, content: '' };
+				}
+				return withFormatting(text, edit, formattingOptions);
+			} else {
+				throw new Error('Array modification not supported yet');
+			}
 		}
 	} else {
 		throw new Error(`Can not add ${typeof lastSegment !== 'number' ? 'index' : 'property'} to parent of type ${parent.type}`);

src/vs/base/test/common/jsonEdit.test.ts

@@ -131,4 +131,29 @@ suite('JSON - edits', () => {
 		let edits = setProperty(content, [-1], 'bar', formatterOptions);
 		assertEdit(content, edits, '[\n  1,\n  2,\n  "bar"\n]');
 	});
+
+	test('remove item in array with one item', () => {
+		let content = '[\n  1\n]';
+		let edits = setProperty(content, [0], void 0, formatterOptions);
+		assertEdit(content, edits, '[]');
+	});
+
+	test('remove item in the middle of the array', () => {
+		let content = '[\n  1,\n  2,\n  3\n]';
+		let edits = setProperty(content, [1], void 0, formatterOptions);
+		assertEdit(content, edits, '[\n  1,\n  3\n]');
+	});
+
+	test('remove last item in the array', () => {
+		let content = '[\n  1,\n  2,\n  "bar"\n]';
+		let edits = setProperty(content, [2], void 0, formatterOptions);
+		assertEdit(content, edits, '[\n  1,\n  2\n]');
+	});
+
+	test('remove last item in the array if ends with comman', () => {
+		let content = '[\n  1,\n  "foo",\n  "bar",\n]';
+		let edits = setProperty(content, [2], void 0, formatterOptions);
+		assertEdit(content, edits, '[\n  1,\n  "foo"\n]');
+	});
+
 });
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