fix: scan for template literal, close #37

Author: antfu

src/core/identifiers.ts

@@ -1,4 +1,4 @@
-import { PrivateName, Expression, Statement, SpreadElement, Node } from '@babel/types'
+import { PrivateName, Expression, Statement, SpreadElement, Node, TSType } from '@babel/types'
 
 export function getIdentifierDeclarations(nodes: Statement[], identifiers = new Set<string>()) {
   for (let node of nodes) {
@@ -54,7 +54,7 @@ export function getIdentifierDeclarations(nodes: Statement[], identifiers = new
   return identifiers
 }
 
-export function getIdentifierUsages(node?: Expression | SpreadElement | PrivateName | Statement | null, identifiers = new Set<string>()) {
+export function getIdentifierUsages(node?: Expression | TSType | SpreadElement | PrivateName | Statement | null, identifiers = new Set<string>()) {
   if (!node)
     return identifiers
 
@@ -114,6 +114,9 @@ export function getIdentifierUsages(node?: Expression | SpreadElement | PrivateN
   else if (node.type === 'ArrowFunctionExpression' || node.type === 'FunctionDeclaration' || node.type === 'FunctionExpression') {
     getIdentifierUsages(node.body, identifiers)
   }
+  else if (node.type === 'TemplateLiteral') {
+    node.expressions.forEach(expr => getIdentifierUsages(expr, identifiers))
+  }
   // else {
   //   console.log(node)
   // }

test/identifiers.test.ts

@@ -1,3 +1,4 @@
+/* eslint-disable no-template-curly-in-string */
 import { parse } from '@babel/parser'
 import { getIdentifierDeclarations, getIdentifierUsages } from '../src/core/identifiers'
 
@@ -51,6 +52,8 @@ describe('identifiers', () => {
       ['() => { foo() + bar; a }', ['foo', 'bar', 'a']],
       ['(function () { foo() + bar })', ['foo', 'bar']],
       ['function foobar() { return foo() + bar }', ['foo', 'bar']],
+      ['`${foo}bar`', ['foo']],
+      ['`${foo(zag)}` + bar', ['foo', 'zag', 'bar']],
     ]
 
     for (const [input, output] of cases) {