fix: preserve text-align on paste from Google Docs (#2208)

* fix: preserve text-align on paste from Google Docs

Add CSS text-align fallback in parseAttrs to extract justification
from inline styles (e.g. `<p style="text-align: center">`), following
the same pattern as the existing spacing/indent CSS fallbacks from
PR #2183. Maps CSS values (left, center, right, justify, start, end)
to OOXML justification values.

* Update packages/super-editor/src/extensions/paragraph/helpers/parseAttrs.js

Co-authored-by: Caio Pizzol <97641911+caio-pizzol@users.noreply.github.com>

* fix: address review — skip default left alignment, fix duplicate declaration

Remove duplicate `let justification` introduced by GitHub suggestion merge.
Skip `left` and `start` text-align values since Google Docs sets
text-align: left on every paragraph — storing it bakes in unnecessary
direct formatting (`<w:jc w:val="left"/>`) on export.

* test: add behavior tests for text-align preservation through paste pipeline

* fix: address review feedback — hoist alignMap, widen assertTextAlignment type

---------

Co-authored-by: Caio Pizzol <97641911+caio-pizzol@users.noreply.github.com>

Author: gpardhivvarma

packages/super-editor/src/extensions/paragraph/helpers/parseAttrs.js

@@ -1,4 +1,5 @@
 const CSS_LENGTH_TO_PT = { pt: 1, px: 72 / 96, in: 72, cm: 28.3465, mm: 2.83465 };
+const CSS_ALIGN_TO_OOXML = { center: 'center', right: 'right', justify: 'justify', end: 'right' };
 
 /**
  * Parse a CSS length value and return { points, unit }.
@@ -104,6 +105,17 @@ export function parseAttrs(node) {
     }
   }
 
+  // CSS inline style fallback for text-align (e.g. Google Docs paste)
+  // Skip 'left' — Google Docs sets text-align: left on every paragraph,
+  // and storing it would bake in unnecessary direct formatting on export.
+  let justification;
+  if (!justification && node.style) {
+    const textAlign = node.style.textAlign;
+    if (textAlign && CSS_ALIGN_TO_OOXML[textAlign]) {
+      justification = CSS_ALIGN_TO_OOXML[textAlign];
+    }
+  }
+
   let attrs = {
     paragraphProperties: {
       styleId: styleId || null,
@@ -119,6 +131,10 @@ export function parseAttrs(node) {
     attrs.paragraphProperties.spacing = spacing;
   }
 
+  if (justification) {
+    attrs.paragraphProperties.justification = justification;
+  }
+
   if (Object.keys(numberingProperties).length > 0) {
     attrs.paragraphProperties.numberingProperties = numberingProperties;
   }

packages/super-editor/src/extensions/paragraph/helpers/parseAttrs.test.js

@@ -234,4 +234,56 @@ describe('parseAttrs', () => {
       expect(result.paragraphProperties.indent).toBeUndefined();
     });
   });
+
+  describe('CSS text-align fallback (Google Docs paste)', () => {
+    it('extracts text-align: center as justification', () => {
+      const node = createMockNode({}, { textAlign: 'center' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBe('center');
+    });
+
+    it('extracts text-align: right as justification', () => {
+      const node = createMockNode({}, { textAlign: 'right' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBe('right');
+    });
+
+    it('extracts text-align: justify as justification', () => {
+      const node = createMockNode({}, { textAlign: 'justify' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBe('justify');
+    });
+
+    it('skips text-align: left (default, avoids unnecessary direct formatting)', () => {
+      const node = createMockNode({}, { textAlign: 'left' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBeUndefined();
+    });
+
+    it('skips text-align: start (maps to left, which is default)', () => {
+      const node = createMockNode({}, { textAlign: 'start' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBeUndefined();
+    });
+
+    it('maps text-align: end to justification right', () => {
+      const node = createMockNode({}, { textAlign: 'end' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBe('right');
+    });
+
+    it('ignores invalid text-align values', () => {
+      const node = createMockNode({}, { textAlign: 'middle' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBeUndefined();
+    });
+
+    it('combines text-align with spacing and indent CSS fallbacks', () => {
+      const node = createMockNode({}, { textAlign: 'center', lineHeight: '1.5', marginLeft: '36pt' });
+      const result = parseAttrs(node);
+      expect(result.paragraphProperties.justification).toBe('center');
+      expect(result.paragraphProperties.spacing.line).toBe(Math.round((1.5 * 240) / 1.15));
+      expect(result.paragraphProperties.indent.left).toBe(720);
+    });
+  });
 });

tests/behavior/fixtures/superdoc.ts

@@ -780,7 +780,7 @@ function createFixture(page: Page, editor: Locator, modKey: string) {
       throw new Error(`assertTextMarkAttrs only supports "link" and "textStyle" via document-api; got "${markName}".`);
     },
 
-    async assertTextAlignment(text: string, expectedAlignment: string, occurrence = 0) {
+    async assertTextAlignment(text: string, expectedAlignment: string | null, occurrence = 0) {
       await expect
         .poll(() =>
           page.evaluate(

tests/behavior/tests/formatting/paste-text-align.spec.ts

@@ -0,0 +1,43 @@
+import { test } from '../../fixtures/superdoc.js';
+
+test.use({ config: { toolbar: 'full', showSelection: true } });
+
+/**
+ * Insert HTML via editor.commands.insertContent to simulate the paste path
+ * (HTML → parseDOM → parseAttrs → document model).
+ */
+async function insertHTML(page: import('@playwright/test').Page, html: string) {
+  await page.evaluate((h) => {
+    const editor = (window as any).editor;
+    editor.commands.insertContent(h);
+  }, html);
+}
+
+test('pasted center-aligned paragraph preserves alignment', async ({ superdoc }) => {
+  await insertHTML(superdoc.page, '<p style="text-align: center">Centered text</p>');
+  await superdoc.waitForStable();
+
+  await superdoc.assertTextAlignment('Centered text', 'center');
+});
+
+test('pasted right-aligned paragraph preserves alignment', async ({ superdoc }) => {
+  await insertHTML(superdoc.page, '<p style="text-align: right">Right text</p>');
+  await superdoc.waitForStable();
+
+  await superdoc.assertTextAlignment('Right text', 'right');
+});
+
+test('pasted justified paragraph preserves alignment', async ({ superdoc }) => {
+  await insertHTML(superdoc.page, '<p style="text-align: justify">Justified text</p>');
+  await superdoc.waitForStable();
+
+  await superdoc.assertTextAlignment('Justified text', 'justify');
+});
+
+test('pasted left-aligned paragraph does not store alignment (default)', async ({ superdoc }) => {
+  await insertHTML(superdoc.page, '<p style="text-align: left">Left text</p>');
+  await superdoc.waitForStable();
+
+  // left is the default — parseAttrs skips it to avoid baking in direct formatting
+  await superdoc.assertTextAlignment('Left text', null);
+});