SOURCE

let a = "select * from ad_message where OBJECT_RRN = ${headers.objectRrn} and";
b = a.match(/(\$\{.*?\.)/g)
c = a.match(/\$\{.*?\}/g)
d = a.match(/\$\{.*?\..*?\}/g)
e = a.match(/(?<=\$\{)(.+?)(?=\})/g)
let reg =new RegExp(/(\$\{.*?\.)/);
f = reg.exec(a);

console.log(b)
console.log(c)
console.log(d)
console.log(e)
console.log(f)