From 2c6bad25010733600505003e2a80b85bf6fd4562 Mon Sep 17 00:00:00 2001
From: syuilo <syuilotan@yahoo.co.jp>
Date: Tue, 27 Nov 2018 02:08:51 +0900
Subject: [PATCH] [MFM] Improve hashtag detection

---
 src/mfm/parser.ts | 20 +++++++++++++-------
 test/mfm.ts       | 29 ++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/mfm/parser.ts b/src/mfm/parser.ts
index 1e9b25b72..322d39493 100644
--- a/src/mfm/parser.ts
+++ b/src/mfm/parser.ts
@@ -30,17 +30,23 @@ function makeNodeWithChildren(name: string, children: Node[], props?: any): Node
 }
 
 function getTrailingPosition(x: string): number {
-	let pendingBracket = 0;
+	const brackets = [
+		['(', ')'],
+		['「', '」'],
+	];
+	const pendingBrackets = [] as any;
 	const end = x.split('').findIndex(char => {
-		if (char == ')') {
-			if (pendingBracket > 0) {
-				pendingBracket--;
+		const closeMatch = brackets.map(x => x[1]).indexOf(char);
+		const openMatch = brackets.map(x => x[0]).indexOf(char);
+		if (closeMatch != -1) {
+			if (pendingBrackets[closeMatch] > 0) {
+				pendingBrackets[closeMatch]--;
 				return false;
 			} else {
 				return true;
 			}
-		} else if (char == '(') {
-			pendingBracket++;
+		} else if (openMatch != -1) {
+			pendingBrackets[openMatch] = (pendingBrackets[openMatch] || 0) + 1;
 			return false;
 		} else {
 			return false;
@@ -156,7 +162,7 @@ const mfm = P.createLanguage({
 			let hashtag = match[1];
 			hashtag = hashtag.substr(0, getTrailingPosition(hashtag));
 			if (hashtag.match(/^[0-9]+$/)) return P.makeFailure(i, 'not a hashtag');
-			if (!['\n', ' ', '(', null, undefined].includes(input[i - 1])) return P.makeFailure(i, 'require space before "#"');
+			if (!['\n', ' ', '(', '「', null, undefined].includes(input[i - 1])) return P.makeFailure(i, 'require space before "#"');
 			return P.makeSuccess(i + ('#' + hashtag).length, makeNode('hashtag', { hashtag: hashtag }));
 		}),
 	//#endregion
diff --git a/test/mfm.ts b/test/mfm.ts
index 98184c9ad..4e29a6926 100644
--- a/test/mfm.ts
+++ b/test/mfm.ts
@@ -213,21 +213,44 @@ describe('Text', () => {
 			});
 
 			it('with brackets', () => {
-				const tokens = analyze('(#foo)');
+				const tokens1 = analyze('(#foo)');
 				assert.deepEqual([
 					text('('),
 					node('hashtag', { hashtag: 'foo' }),
 					text(')'),
+				], tokens1);
+
+				const tokens2 = analyze('「#foo」');
+				assert.deepEqual([
+					text('「'),
+					node('hashtag', { hashtag: 'foo' }),
+					text('」'),
+				], tokens2);
+			});
+
+			it('with mixed brackets', () => {
+				const tokens = analyze('「#foo(bar)」');
+				assert.deepEqual([
+					text('「'),
+					node('hashtag', { hashtag: 'foo(bar)' }),
+					text('」'),
 				], tokens);
 			});
 
 			it('with brackets (space before)', () => {
-				const tokens = analyze('(bar #foo)');
+				const tokens1 = analyze('(bar #foo)');
 				assert.deepEqual([
 					text('(bar '),
 					node('hashtag', { hashtag: 'foo' }),
 					text(')'),
-				], tokens);
+				], tokens1);
+
+				const tokens2 = analyze('「bar #foo」');
+				assert.deepEqual([
+					text('「bar '),
+					node('hashtag', { hashtag: 'foo' }),
+					text('」'),
+				], tokens2);
 			});
 
 			it('disallow number only', () => {