fix(saver): propagate save failures to callers

src/components/modules/saver.ts

@@ -44,6 +44,8 @@ export default class Saver extends Module {
       return this.makeOutput(sanitizedData);
     } catch (e) {
       _.logLabeled(`Saving failed due to the Error %o`, 'error', e);
+
+      throw e;
     }
   }
 

test/cypress/tests/modules/Saver.cy.ts

@@ -1,8 +1,88 @@
 import type EditorJS from '../../../../types/index';
 import Header from '@editorjs/header';
+import ToolMock from '../../fixtures/tools/ToolMock';
 
 describe('Saver module', function () {
   describe('save()', function () {
+    ['throws', 'rejects'].forEach((failureMode) => {
+      it(`should reject with the original error when a tool's save() ${failureMode}`, function () {
+        const saveError = new Error('Tool failed to save');
+        const save = cy.stub(ToolMock.prototype, 'save');
+
+        if (failureMode === 'throws') {
+          save.throws(saveError);
+        } else {
+          save.rejects(saveError);
+        }
+
+        cy.createEditor({
+          tools: {
+            failingTool: ToolMock,
+          },
+          data: {
+            blocks: [
+              {
+                type: 'failingTool',
+                data: { text: 'Unsaved content' },
+              },
+            ],
+          },
+        }).then((editor: EditorJS) => {
+          return editor.save().then(
+            (data) => {
+              assert.fail(`Expected save() to reject, but it resolved with ${JSON.stringify(data)}`);
+            },
+            (error) => {
+              expect(error).to.equal(saveError);
+            }
+          );
+        });
+      });
+    });
+
+    it('should skip invalid blocks and save valid blocks', function () {
+      cy.createEditor({
+        data: {
+          blocks: [
+            {
+              type: 'paragraph',
+              data: { text: '' },
+            },
+            {
+              id: 'valid-block',
+              type: 'paragraph',
+              data: { text: 'Valid content' },
+            },
+          ],
+        },
+      }).then(async (editor: EditorJS) => {
+        const data = await editor.save();
+
+        expect(data.blocks).to.deep.equal([
+          {
+            id: 'valid-block',
+            type: 'paragraph',
+            data: { text: 'Valid content' },
+          },
+        ]);
+      });
+    });
+
+    it('should still reject saving in read-only mode', function () {
+      cy.createEditor({
+        readOnly: true,
+      }).then((editor: EditorJS) => {
+        return editor.save().then(
+          () => {
+            assert.fail('Expected saving in read-only mode to reject');
+          },
+          (error) => {
+            expect(error.message).to.equal('Editor\'s content can not be saved in read-only mode');
+          }
+        );
+      });
+    });
+
     it('should correctly save block if there are some 3rd party (eg. browser extensions) nodes inserted into the layout', function () {
       cy.createEditor({
         data: {