[MFM] Fix hashtag parsing

src/mfm/parser.ts

@@ -110,7 +110,7 @@ const mfm = P.createLanguage({
 			const text = input.substr(i);
 			const match = text.match(/^#([^\s\.,!\?#]+)/i);
 			if (!match) return P.makeFailure(i, 'not a hashtag');
-			if (input[i - 1] != ' ' && input[i - 1] != null) return P.makeFailure(i, 'require space before "#"');
+			if (input[i - 1] != '\n' && input[i - 1] != ' ' && input[i - 1] != null) return P.makeFailure(i, 'require space before "#"');
 			return P.makeSuccess(i + match[0].length, makeNode('hashtag', { hashtag: match[1] }));
 		}),
 	//#endregion

test/mfm.ts

@@ -162,27 +162,48 @@ describe('Text', () => {
 			});
 		});
 
-		it('hashtag', () => {
+		describe('hashtag', () => {
-			const tokens1 = analyze('Strawberry Pasta #alice');
+			it('simple', () => {
+				const tokens = analyze('#alice');
+				assert.deepEqual([
+					node('hashtag', { hashtag: 'alice' })
+				], tokens);
+			});
+
+			it('after line break', () => {
+				const tokens = analyze('foo\n#alice');
+				assert.deepEqual([
+					text('foo\n'),
+					node('hashtag', { hashtag: 'alice' })
+				], tokens);
+			});
+
+			it('with text', () => {
+				const tokens = analyze('Strawberry Pasta #alice');
 				assert.deepEqual([
 					text('Strawberry Pasta '),
 					node('hashtag', { hashtag: 'alice' })
-			], tokens1);
+				], tokens);
+			});
 
-			const tokens2 = analyze('Foo #bar, baz #piyo.');
+			it('ignore comma and period', () => {
+				const tokens = analyze('Foo #bar, baz #piyo.');
 				assert.deepEqual([
 					text('Foo '),
 					node('hashtag', { hashtag: 'bar' }),
 					text(', baz '),
 					node('hashtag', { hashtag: 'piyo' }),
 					text('.'),
-			], tokens2);
+				], tokens);
+			});
 
-			const tokens3 = analyze('#Foo!');
+			it('ignore exclamation mark', () => {
+				const tokens = analyze('#Foo!');
 				assert.deepEqual([
 					node('hashtag', { hashtag: 'Foo' }),
 					text('!'),
-			], tokens3);
+				], tokens);
+			});
 		});
 
 		describe('quote', () => {