convert native exceptions to shrimp exceptions

src/vm.ts

@@ -562,9 +562,37 @@ export class VM {
           }
 
           // Call the native function with bound args
-          const result = await fn.fn.call(this, ...nativeArgs)
-          this.stack.push(result)
-          break
+          try {
+            const result = await fn.fn.call(this, ...nativeArgs)
+            this.stack.push(result)
+            break
+          } catch (error) {
+            const errorMessage = error instanceof Error ? error.message : String(error)
+            const errorValue = toValue(errorMessage)
+
+            // no exception handlers, let it crash
+            if (this.exceptionHandlers.length === 0) {
+              throw new Error(`Uncaught exception in native function: ${errorMessage}`)
+            }
+
+            // use existing THROW logic
+            const throwHandler = this.exceptionHandlers.pop()!
+
+            while (this.callStack.length > throwHandler.callStackDepth)
+              this.callStack.pop()
+
+            this.scope = throwHandler.scope
+            this.stack.push(errorValue)
+
+            // Jump to `finally` if present, otherwise jump to `catch`
+            const targetAddress = throwHandler.finallyAddress !== undefined
+              ? throwHandler.finallyAddress
+              : throwHandler.catchAddress
+
+            // subtract 1 because pc will be incremented
+            this.pc = targetAddress - 1
+            break
+          }
         }
 
         if (fn.type !== 'function')

tests/native.test.ts

@@ -2201,4 +2201,163 @@ test("raw flag - raw function can return any Value type", async () => {
       expect(numbers.value).toEqual([toValue(1), toValue(2), toValue(3)])
     }
   }
+})
+
+test('native function error caught by try/catch - direct call', async () => {
+  const bytecode = toBytecode(`
+    PUSH_TRY .catch
+    LOAD failing_fn
+    PUSH 0
+    PUSH 0
+    CALL
+    POP_TRY
+    JUMP .end
+
+    .catch:
+      STORE err
+      PUSH 'caught: '
+      LOAD err
+      STR_CONCAT #2
+      JUMP .end
+
+    .end:
+    HALT
+  `)
+
+  const vm = new VM(bytecode)
+  vm.set('failing_fn', () => {
+    throw new Error('native error')
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'string', value: 'caught: native error' })
+})
+
+test('native function error caught by try/catch - inside reef function', async () => {
+  const bytecode = toBytecode(`
+    MAKE_FUNCTION () .try_body
+    STORE call_native
+    JUMP .after_try_body
+
+    .try_body:
+      LOAD failing_fn
+      PUSH 0
+      PUSH 0
+      CALL
+      RETURN
+
+    .after_try_body:
+
+    PUSH_TRY .catch
+    LOAD call_native
+    PUSH 0
+    PUSH 0
+    CALL
+    POP_TRY
+    JUMP .end
+
+    .catch:
+      STORE err
+      PUSH 'caught: '
+      LOAD err
+      STR_CONCAT #2
+      JUMP .end
+
+    .end:
+    HALT
+  `)
+
+  const vm = new VM(bytecode)
+  vm.set('failing_fn', () => {
+    throw new Error('native error')
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'string', value: 'caught: native error' })
+})
+
+test('async native function error caught by try/catch', async () => {
+  const bytecode = toBytecode(`
+    PUSH_TRY .catch
+    LOAD async_fail
+    PUSH 0
+    PUSH 0
+    CALL
+    POP_TRY
+    JUMP .end
+
+    .catch:
+      STORE err
+      PUSH 'async caught: '
+      LOAD err
+      STR_CONCAT #2
+      JUMP .end
+
+    .end:
+    HALT
+  `)
+
+  const vm = new VM(bytecode)
+  vm.set('async_fail', async () => {
+    await new Promise(resolve => setTimeout(resolve, 1))
+    throw new Error('async error')
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'string', value: 'async caught: async error' })
+})
+
+test('native function error with finally block', async () => {
+  const bytecode = toBytecode(`
+    PUSH 0
+    STORE cleanup_count
+
+    PUSH_TRY .catch
+    PUSH_FINALLY .finally
+    LOAD failing_fn
+    PUSH 0
+    PUSH 0
+    CALL
+    POP_TRY
+    JUMP .finally
+
+    .catch:
+      STORE err
+      PUSH 'error handled'
+      JUMP .finally
+
+    .finally:
+      LOAD cleanup_count
+      PUSH 1
+      ADD
+      STORE cleanup_count
+
+    HALT
+  `)
+
+  const vm = new VM(bytecode)
+  vm.set('failing_fn', () => {
+    throw new Error('native error')
+  })
+
+  await vm.run()
+  const cleanupCount = vm.scope.get('cleanup_count')
+  expect(cleanupCount).toEqual({ type: 'number', value: 1 })
+})
+
+test('uncaught native function error crashes VM', async () => {
+  const bytecode = toBytecode(`
+    LOAD failing_fn
+    PUSH 0
+    PUSH 0
+    CALL
+    HALT
+  `)
+
+  const vm = new VM(bytecode)
+  vm.set('failing_fn', () => {
+    throw new Error('uncaught error')
+  })
+
+  await expect(vm.run()).rejects.toThrow('Uncaught exception in native function: uncaught error')
 })