Fix wrong indentation with nested ordered list unnesting list on edit (#7300)

src/editor/deserialize.ts

@@ -129,7 +129,9 @@ function parseElement(n: HTMLElement, partCreator: PartCreator, lastNode: HTMLEl
         case "U":
             return partCreator.plain(`<u>${n.textContent}</u>`);
         case "LI": {
-            const indent = "  ".repeat(state.listDepth - 1);
+            const BASE_INDENT = 4;
+            const depth = state.listDepth - 1;
+            const indent = " ".repeat(BASE_INDENT * depth);
             if (n.parentElement.nodeName === "OL") {
                 // The markdown parser doesn't do nested indexed lists at all, but this supports it anyway.
                 const index = state.listIndex[state.listIndex.length - 1];

test/editor/deserialize-test.js

@@ -18,6 +18,8 @@ import '../skinned-sdk'; // Must be first for skinning to work
 import { parseEvent } from "../../src/editor/deserialize";
 import { createPartCreator } from "./mock";
 
+const FOUR_SPACES = " ".repeat(4);
+
 function htmlMessage(formattedBody, msgtype = "m.text") {
     return {
         getContent() {
@@ -235,6 +237,26 @@ describe('editor/deserialize', function() {
             expect(parts[3]).toStrictEqual({ type: "newline", text: "\n" });
             expect(parts[4]).toStrictEqual({ type: "plain", text: "3. Finish" });
         });
+        it('nested unordered lists', () => {
+            const html = "<ul><li>Oak<ul><li>Spruce<ul><li>Birch</li></ul></li></ul></li></ul>";
+            const parts = normalize(parseEvent(htmlMessage(html), createPartCreator()));
+            expect(parts.length).toBe(5);
+            expect(parts[0]).toStrictEqual({ type: "plain", text: "- Oak" });
+            expect(parts[1]).toStrictEqual({ type: "newline", text: "\n" });
+            expect(parts[2]).toStrictEqual({ type: "plain", text: `${FOUR_SPACES}- Spruce` });
+            expect(parts[3]).toStrictEqual({ type: "newline", text: "\n" });
+            expect(parts[4]).toStrictEqual({ type: "plain", text: `${FOUR_SPACES.repeat(2)}- Birch` });
+        });
+        it('nested ordered lists', () => {
+            const html = "<ol><li>Oak<ol><li>Spruce<ol><li>Birch</li></ol></li></ol></li></ol>";
+            const parts = normalize(parseEvent(htmlMessage(html), createPartCreator()));
+            expect(parts.length).toBe(5);
+            expect(parts[0]).toStrictEqual({ type: "plain", text: "1. Oak" });
+            expect(parts[1]).toStrictEqual({ type: "newline", text: "\n" });
+            expect(parts[2]).toStrictEqual({ type: "plain", text: `${FOUR_SPACES}1. Spruce` });
+            expect(parts[3]).toStrictEqual({ type: "newline", text: "\n" });
+            expect(parts[4]).toStrictEqual({ type: "plain", text: `${FOUR_SPACES.repeat(2)}1. Birch` });
+        });
         it('mx-reply is stripped', function() {
             const html = "<mx-reply>foo</mx-reply>bar";
             const parts = normalize(parseEvent(htmlMessage(html), createPartCreator()));