ENG-2326 Indent every line of a multi-line Roam block in Roam's markdown output

apps/roam/src/utils/__tests__/pageToMarkdown.test.ts

@@ -0,0 +1,72 @@
+import { describe, expect, it, vi } from "vitest";
+import type { TreeNode, ViewType } from "roamjs-components/types";
+
+vi.mock("roamjs-components/queries/getFullTreeByParentUid", () => ({
+  default: () => ({ children: [] }),
+}));
+
+// Runs before the imports below: getDiscourseNodes calls generateUID at module load.
+vi.hoisted(() => {
+  (globalThis as { window?: unknown }).window = {
+    roamAlphaAPI: { util: { generateUID: () => "someUid" } },
+  };
+});
+
+import { toMarkdown } from "~/utils/pageToMarkdown";
+
+const block = (text: string, children: TreeNode[] = []): TreeNode =>
+  ({ text, children, order: 0, uid: "" }) as unknown as TreeNode;
+
+const opts = {
+  refs: false,
+  embeds: false,
+  simplifiedFilename: false,
+  maxFilenameLength: 64,
+  allNodes: [],
+  removeSpecialCharacters: false,
+  linkType: "wikilinks",
+};
+
+const render = ({
+  c,
+  v,
+  flatten,
+}: {
+  c: TreeNode;
+  v?: ViewType;
+  flatten?: boolean;
+}): string => toMarkdown({ c, v, opts: { ...opts, flatten } });
+
+const codeBlock = "```js\nconst a = 1;\n\nconst b = 2;\n```";
+
+describe("toMarkdown multi-line blocks", () => {
+  it("indents every line of a top-level bullet to its content column", () => {
+    expect(render({ c: block(`intro\n${codeBlock}`) })).toBe(
+      "- intro\n  ```js\n  const a = 1;\n\n  const b = 2;\n  ```",
+    );
+  });
+
+  it("indents every line of a nested bullet to its content column", () => {
+    expect(render({ c: block("parent", [block(`intro\n${codeBlock}`)]) })).toBe(
+      "- parent\n    - intro\n      ```js\n      const a = 1;\n\n      const b = 2;\n      ```",
+    );
+  });
+
+  it("indents to the wider content column of a numbered item", () => {
+    expect(render({ c: block("first\nsecond"), v: "numbered" })).toBe(
+      "1. first\n   second",
+    );
+  });
+
+  it("leaves continuation lines alone when flattening", () => {
+    expect(
+      render({ c: block("parent", [block("first\nsecond")]), flatten: true }),
+    ).toBe("- parent\n- first\nsecond");
+  });
+
+  it("leaves continuation lines alone in the document view type", () => {
+    expect(
+      render({ c: block("parent", [block("first\nsecond")]), v: "document" }),
+    ).toBe("parent\n\n    first\nsecond\n");
+  });
+});

apps/roam/src/utils/pageToMarkdown.ts

@@ -109,6 +109,20 @@ const handleFrontmatter = ({
   return output;
 };
 
+const indentContinuationLines = ({
+  text,
+  width,
+}: {
+  text: string;
+  width: number;
+}): string => {
+  const padding = "".padStart(width, " ");
+  return text
+    .split("\n")
+    .map((line, index) => (index === 0 || !line ? line : `${padding}${line}`))
+    .join("\n");
+};
+
 export const toMarkdown = ({
   c,
   i = 0,
@@ -191,6 +205,15 @@ export const toMarkdown = ({
       : v;
   const viewTypePrefix = viewTypeToPrefix[effectiveViewType];
   const headingPrefix = c.heading ? `${"".padStart(c.heading, "#")} ` : "";
+  // CommonMark ends a list item at a column-0 fence, heading, quote or table,
+  // so continuation lines must sit at the item's content column.
+  const blockText =
+    flatten || effectiveViewType === "document"
+      ? finalProcessedText
+      : indentContinuationLines({
+          text: finalProcessedText,
+          width: indentation.length + viewTypePrefix.length,
+        });
   const childrenMarkdown = (c.children || [])
     .filter((nested) => !!nested.text || !!nested.children?.length)
     .map((nested) => {
@@ -206,7 +229,7 @@ export const toMarkdown = ({
     .join("");
   const lineBreak = v === "document" ? "\n" : "";
 
-  return `${indentation}${viewTypePrefix}${headingPrefix}${finalProcessedText}${lineBreak}${childrenMarkdown}`;
+  return `${indentation}${viewTypePrefix}${headingPrefix}${blockText}${lineBreak}${childrenMarkdown}`;
 };
 
 export const pageToMarkdown = async (