client: replace array concat with Array.prototype.flat

packages/client/src/components/cw-button.vue

@@ -9,7 +9,6 @@
 import { computed } from 'vue';
 import { length } from 'stringz';
 import * as foundkey from 'foundkey-js';
-import { concat } from '@/scripts/array';
 import { i18n } from '@/i18n';
 
 const props = defineProps<{
@@ -22,12 +21,12 @@ const emit = defineEmits<{
 }>();
 
 const label = computed(() => {
-	return concat([
+	return [
 		props.note.text ? [i18n.t('_cw.chars', { count: length(props.note.text) })] : [],
 		props.note.files && props.note.files.length !== 0 ? [i18n.t('_cw.files', { count: props.note.files.length }) ] : [],
 		props.note.poll != null ? [i18n.ts.poll] : [],
 		props.note.renoteId != null ? [i18n.ts.quote] : [],
-	] as string[][]).join(' / ');
+	].flat().join(' / ');
 });
 
 const toggle = () => {

packages/client/src/components/mfm.ts

@@ -4,7 +4,6 @@ import MkUrl from '@/components/global/url.vue';
 import MkLink from '@/components/link.vue';
 import MkMention from '@/components/mention.vue';
 import MkEmoji from '@/components/global/emoji.vue';
-import { concat } from '@/scripts/array';
 import MkFormula from '@/components/formula.vue';
 import MkCode from '@/components/code.vue';
 import MkSearch from '@/components/mfm-search.vue';
@@ -50,7 +49,7 @@ export default defineComponent({
 			return t.match(/^[0-9.]+s$/) ? t : null;
 		};
 
-		const genEl = (ast: mfm.MfmNode[]) => concat(ast.map((token): VNode[] => {
+		const genEl = (ast: mfm.MfmNode[]) => ast.map((token): VNode[] => {
 			switch (token.type) {
 				case 'text': {
 					const text = token.props.text.replace(/(\r\n|\n|\r)/g, '\n');
@@ -314,7 +313,7 @@ export default defineComponent({
 					return [];
 				}
 			}
-		}));
+		}).flat();
 
 		// Parse ast to DOM
 		return h('span', genEl(ast));

packages/client/src/scripts/array.ts

@@ -15,19 +15,12 @@ export function count<T>(a: T, xs: T[]): number {
 	return countIf(x => x === a, xs);
 }
 
-/**
- * Concatenate an array of arrays
- */
-export function concat<T>(xss: T[][]): T[] {
-	return ([] as T[]).concat(...xss);
-}
-
 /**
  * Intersperse the element between the elements of the array
  * @param sep The element to be interspersed
  */
 export function intersperse<T>(sep: T, xs: T[]): T[] {
-	return concat(xs.map(x => [sep, x])).slice(1);
+	return xs.map(x => [sep, x]).flat().slice(1);
 }
 
 /**