Add error causes

If an error is caused by a specific value, that value is used as the
error cause.

src/estree-util-value-to-estree.ts

@@ -254,7 +254,7 @@ export function valueToEstree(value: unknown, options: Options = {}): Expression
    */
   function analyze(val: unknown): undefined {
     if (typeof val === 'function') {
-      throw new TypeError(`Unsupported value: ${val}`)
+      throw new TypeError(`Unsupported value: ${val}`, { cause: val })
     }
 
     if (typeof val !== 'object') {
@@ -272,7 +272,7 @@ export function valueToEstree(value: unknown, options: Options = {}): Expression
       }
       if (stack.includes(val)) {
         if (!options.preserveReferences) {
-          throw new Error(`Found recursive value: ${val}`)
+          throw new Error(`Found circular reference: ${val}`, { cause: val })
         }
         const parent = stack.at(-1)!
         const parentContext = collectedContexts.get(parent)!
@@ -315,7 +315,7 @@ export function valueToEstree(value: unknown, options: Options = {}): Expression
         analyze((val as Record<string | symbol, unknown>)[key])
       }
     } else {
-      throw new TypeError(`Unsupported value: ${val}`)
+      throw new TypeError(`Unsupported value: ${val}`, { cause: val })
     }
     stack.pop()
   }
@@ -367,7 +367,7 @@ export function valueToEstree(value: unknown, options: Options = {}): Expression
         return methodCall(identifier('Symbol'), 'for', [literal(val.description)])
       }
 
-      throw new TypeError(`Only global symbols are supported, got: ${String(val)}`)
+      throw new TypeError(`Only global symbols are supported, got: ${String(val)}`, { cause: val })
     }
 
     const context = collectedContexts.get(val)

src/test.ts

@@ -1,4 +1,4 @@
-import * as assert from 'node:assert/strict'
+import assert from 'node:assert/strict'
 import { test } from 'node:test'
 
 import { generate } from 'astring'
@@ -34,18 +34,58 @@ testFixturesDirectory({
 })
 
 test('throw for local symbols', () => {
+  const symbol = Symbol('local')
   assert.throws(
-    () => valueToEstree(Symbol('local')),
-    new TypeError('Only global symbols are supported, got: Symbol(local)')
+    () => valueToEstree(symbol),
+    (error) => {
+      assert(error instanceof TypeError)
+      assert.equal(error.message, 'Only global symbols are supported, got: Symbol(local)')
+      assert.equal(error.cause, symbol)
+      return true
+    }
   )
 })
 
 test('throw for unsupported values', () => {
-  assert.throws(() => valueToEstree(() => null), new TypeError('Unsupported value: () => null'))
+  const fn = (): null => null
+  assert.throws(
+    () => valueToEstree(fn),
+    (error) => {
+      assert(error instanceof TypeError)
+      assert.equal(error.message, 'Unsupported value: () => null')
+      assert.equal(error.cause, fn)
+      return true
+    }
+  )
+
   class A {
     a = ''
   }
-  assert.throws(() => valueToEstree(new A()), new TypeError('Unsupported value: [object Object]'))
+
+  const a = new A()
+  assert.throws(
+    () => valueToEstree(a),
+    (error) => {
+      assert(error instanceof TypeError)
+      assert.equal(error.message, 'Unsupported value: [object Object]')
+      assert.equal(error.cause, a)
+      return true
+    }
+  )
+})
+
+test('throw for cyclic references', () => {
+  const object: Record<string, unknown> = {}
+  object.reference = object
+  assert.throws(
+    () => valueToEstree(object),
+    (error) => {
+      assert(error instanceof Error)
+      assert.equal(error.message, 'Found circular reference: [object Object]')
+      assert.equal(error.cause, object)
+      return true
+    }
+  )
 })
 
 test('transform to json on unsupported values w/ `instanceAsObject`', () => {

tsconfig.json

@@ -9,6 +9,6 @@
     "outDir": "dist",
     "sourceMap": true,
     "strict": true,
-    "target": "es2020"
+    "target": "es2022"
   }
 }