test: add tests for isNodeEmpty function (#574)

Author: ReFFaT

src/utils/nodes.test.ts

@@ -0,0 +1,37 @@
+import {Schema} from 'prosemirror-model';
+
+import {isNodeEmpty} from './nodes';
+
+const schema = new Schema({
+    nodes: {
+        doc: {content: 'block+'},
+        yfm_cut_content: {content: 'block+'},
+        paragraph: {content: 'inline*', group: 'block'},
+        text: {group: 'inline'},
+        code_block: {content: 'inline*', group: 'block'},
+    },
+});
+
+describe('isNodeEmpty', () => {
+    it('yfm_cut_content with an empty paragraph', () => {
+        const emptyParagraph = schema.nodes.paragraph.create();
+        const yfmCutContent = schema.nodes.yfm_cut_content.create(null, emptyParagraph);
+
+        expect(isNodeEmpty(yfmCutContent)).toBe(true);
+    });
+
+    it('yfm_cut_content with a paragraph containing text', () => {
+        const textNode = schema.text('Hello, world!');
+        const paragraphWithText = schema.nodes.paragraph.create(null, textNode);
+        const yfmCutContent = schema.nodes.yfm_cut_content.create(null, paragraphWithText);
+
+        expect(isNodeEmpty(yfmCutContent)).toBe(false);
+    });
+
+    it('fm_cut_content with a non-paragraph block', () => {
+        const codeBlock = schema.nodes.code_block.create();
+        const yfmCutContent = schema.nodes.yfm_cut_content.create(null, codeBlock);
+
+        expect(isNodeEmpty(yfmCutContent)).toBe(false);
+    });
+});