refactor mfm extract (#7434)

* refactor extractCustomEmojisFromMfm()

* refactor extract-hashtags

* refactor extract-mentions

* refactor extract-hashtags

* refactor extract-url-from-mfm

* refactor extract-mentions

4 files changed, 28 insertions, 47 deletions

diff --git a/src/misc/extract-custom-emojis-from-mfm.ts b/src/misc/extract-custom-emojis-from-mfm.ts
index f1477a79f0..ef2cb1fd6c 100644
--- a/src/misc/extract-custom-emojis-from-mfm.ts
+++ b/src/misc/extract-custom-emojis-from-mfm.ts
@@ -2,17 +2,13 @@ import * as mfm from 'mfm-js';
 import { unique } from '@/prelude/array';
 
 export function extractCustomEmojisFromMfm(nodes: mfm.MfmNode[]): string[] {
-	const emojiNodes = [] as mfm.MfmEmojiCode[];
+	const emojis = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'emojiCode') emojiNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'emojiCode' && node.props.name.length <= 100) {
+			emojis.push(node.props.name);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const emojis = emojiNodes.filter(x => x.props.name.length <= 100).map(x => x.props.name!);
 	return unique(emojis);
 }
diff --git a/src/misc/extract-hashtags.ts b/src/misc/extract-hashtags.ts
index 9961755ccd..f89b699a94 100644
--- a/src/misc/extract-hashtags.ts
+++ b/src/misc/extract-hashtags.ts
@@ -1,18 +1,14 @@
 import * as mfm from 'mfm-js';
 import { unique } from '@/prelude/array';
 
-export default function(nodes: mfm.MfmNode[]): string[] {
-	const hashtagNodes = [] as mfm.MfmHashtag[];
+export function extractHashtags(nodes: mfm.MfmNode[]): string[] {
+	const hashtags = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'hashtag') hashtagNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'hashtag') {
+			hashtags.push(node.props.hashtag);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const hashtags = hashtagNodes.map(x => x.props.hashtag);
 	return unique(hashtags);
 }
diff --git a/src/misc/extract-mentions.ts b/src/misc/extract-mentions.ts
index a9d4b378f3..a0e2fb6d57 100644
--- a/src/misc/extract-mentions.ts
+++ b/src/misc/extract-mentions.ts
@@ -2,18 +2,15 @@
 
 import * as mfm from 'mfm-js';
 
-export default function(nodes: mfm.MfmNode[]): mfm.MfmMention['props'][] {
+export function extractMentions(nodes: mfm.MfmNode[]): mfm.MfmMention['props'][] {
 	// TODO: 重複を削除
-	const mentionNodes = [] as mfm.MfmMention[];
+	const mentions = [] as mfm.MfmMention['props'][];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'mention') mentionNodes.push(node);
-			else if (node.children) scan(node.children);
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'mention') {
+			mentions.push(node.props);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	return mentionNodes.map(x => x.props);
+	return mentions;
 }
diff --git a/src/misc/extract-url-from-mfm.ts b/src/misc/extract-url-from-mfm.ts
index aa7f5f2540..ec3b019ea5 100644
--- a/src/misc/extract-url-from-mfm.ts
+++ b/src/misc/extract-url-from-mfm.ts
@@ -6,29 +6,21 @@ import { unique } from '@/prelude/array';
 const removeHash = (x: string) => x.replace(/#[^#]*$/, '');
 
 export function extractUrlFromMfm(nodes: mfm.MfmNode[], respectSilentFlag = true): string[] {
-	const urlNodes = [] as (mfm.MfmUrl | mfm.MfmLink)[];
+	let urls = [] as string[];
 
-	function scan(nodes: mfm.MfmNode[]) {
-		for (const node of nodes) {
-			if (node.type === 'url') {
-				urlNodes.push(node);
-			} else if (node.type === 'link') {
-				if (!respectSilentFlag || !node.props.silent) {
-					urlNodes.push(node);
-				}
-			} else if (node.children) {
-				scan(node.children);
-			}
+	mfm.inspect(nodes, (node) => {
+		if (node.type === 'url') {
+			urls.push(node.props.url);
+		} else if (node.type === 'link' && (!respectSilentFlag || !node.props.silent)) {
+			urls.push(node.props.url);
 		}
-	}
+	});
 
-	scan(nodes);
-
-	const urls = unique(urlNodes.map(x => x.props.url));
+	urls = unique(urls);
 
 	return urls.reduce((array, url) => {
-		const removed = removeHash(url);
-		if (!array.map(x => removeHash(x)).includes(removed)) array.push(url);
+		const urlWithoutHash = removeHash(url);
+		if (!array.map(x => removeHash(x)).includes(urlWithoutHash)) array.push(url);
 		return array;
 	}, [] as string[]);
 }