🏋️‍♀️ Jats-to-myst transform to lift figure caption titles

packages/jats-to-myst/src/transforms/figureCaptions.spec.ts

@@ -0,0 +1,65 @@
+import { describe, expect, test } from 'vitest';
+import { figCaptionTitleTransform } from './figureCaptions';
+
+describe('figCaptionTitleTransform', () => {
+  test('figure caption title is moved up', () => {
+    const tree = {
+      type: 'root',
+      children: [
+        {
+          type: 'fig',
+          children: [
+            {
+              type: 'caption',
+              children: [
+                {
+                  type: 'title',
+                  children: [
+                    {
+                      type: 'text',
+                      value: 'My Title',
+                    },
+                  ],
+                },
+                {
+                  type: 'text',
+                  value: 'My content',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    };
+    const result = {
+      type: 'root',
+      children: [
+        {
+          type: 'fig',
+          children: [
+            {
+              type: 'title',
+              children: [
+                {
+                  type: 'text',
+                  value: 'My Title',
+                },
+              ],
+            },
+            {
+              type: 'caption',
+              children: [
+                {
+                  type: 'text',
+                  value: 'My content',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    };
+    figCaptionTitleTransform(tree);
+    expect(tree).toEqual(result);
+  });
+});

packages/jats-to-myst/src/transforms/figureCaptions.ts

@@ -0,0 +1,27 @@
+import type { Plugin } from 'unified';
+import type { Heading } from 'myst-spec';
+import type { GenericParent } from 'myst-common';
+import { copyNode } from 'myst-common';
+import { select, selectAll } from 'unist-util-select';
+import { remove } from 'unist-util-remove';
+import { Tags } from 'jats-tags';
+
+export type Section = Omit<Heading, 'type'> & { type: 'section' };
+
+/**
+ * Move figure > caption > titles up to the figure
+ */
+export function figCaptionTitleTransform(tree: GenericParent) {
+  const figures = selectAll(Tags.fig, tree) as GenericParent[];
+  figures.forEach((figure) => {
+    const captionTitle = select('caption > title', figure);
+    if (!captionTitle) return;
+    figure.children = [copyNode(captionTitle), ...figure.children];
+    captionTitle.type = '__delete__';
+  });
+  remove(tree, '__delete__');
+}
+
+export const figCaptionTitlePlugin: Plugin<[], GenericParent, GenericParent> = () => (tree) => {
+  figCaptionTitleTransform(tree);
+};

packages/jats-to-myst/src/transforms/index.ts

@@ -5,15 +5,18 @@ import type { VFile } from 'vfile';
 import { sectionTransform } from './sections.js';
 import { typographyTransform } from './typography.js';
 import { admonitionTransform } from './admonitions.js';
+import { figCaptionTitleTransform } from './figureCaptions.js';
 
 export { sectionTransform, sectionPlugin } from './sections.js';
 export { typographyTransform, typographyPlugin } from './typography.js';
 export { admonitionTransform, admonitionPlugin } from './admonitions.js';
+export { figCaptionTitleTransform, figCaptionTitlePlugin } from './figureCaptions.js';
 
 export function basicTransformations(tree: GenericParent, file: VFile) {
   sectionTransform(tree);
   typographyTransform(tree);
   admonitionTransform(tree, file);
+  figCaptionTitleTransform(tree);
 }
 
 export const basicTransformationsPlugin: Plugin<[], GenericParent, GenericParent> =