The equivalent is simply:
import "./filename";
Here are some of the possible syntax variations:
import defaultMember from "module-name";
import * as name from "module-name";
import { member } from "module-name";
import { member as alias } from "module-name";
import { member1 , member2 } from "module-name";
import { member1 , member2 as alias2 , [...] } from "module-name";
import defaultMember, { member [ , [...] ] } from "module-name";
import defaultMember, * as name from "module-name";
import "module-name";
SOURCE: MDN
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…