fix: detection usages in inline functions, close #15

Author: antfu

src/core/identifiers.ts

@@ -53,7 +53,10 @@ export function getIdentifierUsages(node?: Expression | SpreadElement | PrivateN
   if (!node)
     return identifiers
 
-  if (node.type === 'ExpressionStatement') {
+  if (node.type === 'BlockStatement') {
+    node.body.forEach(child => getIdentifierUsages(child, identifiers))
+  }
+  else if (node.type === 'ExpressionStatement') {
     getIdentifierUsages(node.expression, identifiers)
   }
   else if (node.type === 'Identifier') {
@@ -109,6 +112,12 @@ export function getIdentifierUsages(node?: Expression | SpreadElement | PrivateN
       getIdentifierUsages(arg as Expression, identifiers)
     })
   }
+  else if (node.type === 'ArrowFunctionExpression' || node.type === 'FunctionDeclaration' || node.type === 'FunctionExpression') {
+    getIdentifierUsages(node.body, identifiers)
+  }
+  else if (node.type === 'ReturnStatement') {
+    getIdentifierUsages(node.argument, identifiers)
+  }
   // else {
   //   console.log(node)
   // }

test/identifiers.test.ts

@@ -47,6 +47,10 @@ describe('identifiers', () => {
       ['[a,b,[c,{d}],...args]', ['a', 'b', 'c', 'd', 'args']],
       ['new Foo(a,[b])', ['Foo', 'a', 'b']],
       ['new RC.Foo()', ['RC']],
+      ['() => foo(bar)', ['foo', 'bar']],
+      ['() => { foo() + bar; a }', ['foo', 'bar', 'a']],
+      ['(function () { foo() + bar })', ['foo', 'bar']],
+      ['function foobar() { return foo() + bar }', ['foo', 'bar']],
     ]
 
     for (const [input, output] of cases) {