Add Env::RunScript

This is a thin wrapper around napi_run_script.

Refs: nodejs/node#15216
PR-URL: #616
Reviewed-By: Nicola Del Gobbo <nicoladelgobbo@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Kevin Eady <kevin.c.eady@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

Author: tniessen

doc/env.md

@@ -61,3 +61,17 @@ Napi::Error Napi::Env::GetAndClearPendingException();
 ```
 
 Returns an `Napi::Error` object representing the environment's pending exception, if any.
+
+### RunScript
+
+```cpp
+Napi::Value Napi::Env::RunScript(____ script);
+```
+- `[in] script`: A string containing JavaScript code to execute.
+
+Runs JavaScript code contained in a string and returns its result.
+
+The `script` can be any of the following types:
+- [`Napi::String`](string.md)
+- `const char *`
+- `const std::string &`

napi-inl.h

@@ -319,6 +319,22 @@ inline Error Env::GetAndClearPendingException() {
   return Error(_env, value);
 }
 
+inline Value Env::RunScript(const char* utf8script) {
+  String script = String::New(_env, utf8script);
+  return RunScript(script);
+}
+
+inline Value Env::RunScript(const std::string& utf8script) {
+  return RunScript(utf8script.c_str());
+}
+
+inline Value Env::RunScript(String script) {
+  napi_value result;
+  napi_status status = napi_run_script(_env, script, &result);
+  NAPI_THROW_IF_FAILED(_env, status, Undefined());
+  return Value(_env, result);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Value class
 ////////////////////////////////////////////////////////////////////////////////

napi.h

@@ -178,6 +178,10 @@ namespace Napi {
     bool IsExceptionPending() const;
     Error GetAndClearPendingException();
 
+    Value RunScript(const char* utf8script);
+    Value RunScript(const std::string& utf8script);
+    Value RunScript(String script);
+
   private:
     napi_env _env;
   };

test/binding.cc

@@ -39,6 +39,7 @@ Object InitObject(Env env);
 Object InitObjectDeprecated(Env env);
 #endif // !NODE_ADDON_API_DISABLE_DEPRECATED
 Object InitPromise(Env env);
+Object InitRunScript(Env env);
 #if (NAPI_VERSION > 3)
 Object InitThreadSafeFunctionCtx(Env env);
 Object InitThreadSafeFunctionExistingTsfn(Env env);
@@ -92,6 +93,7 @@ Object Init(Env env, Object exports) {
   exports.Set("object_deprecated", InitObjectDeprecated(env));
 #endif // !NODE_ADDON_API_DISABLE_DEPRECATED
   exports.Set("promise", InitPromise(env));
+  exports.Set("run_script", InitRunScript(env));
 #if (NAPI_VERSION > 3)
   exports.Set("threadsafe_function_ctx", InitThreadSafeFunctionCtx(env));
   exports.Set("threadsafe_function_existing_tsfn", InitThreadSafeFunctionExistingTsfn(env));

test/binding.gyp

@@ -36,6 +36,7 @@
         'object/object.cc',
         'object/set_property.cc',
         'promise.cc',
+        'run_script.cc',
         'threadsafe_function/threadsafe_function_ctx.cc',
         'threadsafe_function/threadsafe_function_existing_tsfn.cc',
         'threadsafe_function/threadsafe_function_ptr.cc',

test/index.js

@@ -39,6 +39,7 @@ let testModules = [
   'object/object_deprecated',
   'object/set_property',
   'promise',
+  'run_script',
   'threadsafe_function/threadsafe_function_ctx',
   'threadsafe_function/threadsafe_function_existing_tsfn',
   'threadsafe_function/threadsafe_function_ptr',

test/run_script.cc

@@ -0,0 +1,55 @@
+#include "napi.h"
+
+using namespace Napi;
+
+namespace {
+
+Value RunPlainString(const CallbackInfo& info) {
+  Env env = info.Env();
+  return env.RunScript("1 + 2 + 3");
+}
+
+Value RunStdString(const CallbackInfo& info) {
+  Env env = info.Env();
+  std::string str = "1 + 2 + 3";
+  return env.RunScript(str);
+}
+
+Value RunJsString(const CallbackInfo& info) {
+  Env env = info.Env();
+  return env.RunScript(info[0].As<String>());
+}
+
+Value RunWithContext(const CallbackInfo& info) {
+  Env env = info.Env();
+
+  Array keys = info[1].As<Object>().GetPropertyNames();
+  std::string code = "(";
+  for (unsigned int i = 0; i < keys.Length(); i++) {
+    if (i != 0) code += ",";
+    code += keys.Get(i).As<String>().Utf8Value();
+  }
+  code += ") => " + info[0].As<String>().Utf8Value();
+
+  Value ret = env.RunScript(code);
+  Function fn = ret.As<Function>();
+  std::vector<napi_value> args;
+  for (unsigned int i = 0; i < keys.Length(); i++) {
+    Value key = keys.Get(i);
+    args.push_back(info[1].As<Object>().Get(key));
+  }
+  return fn.Call(args);
+}
+
+} // end anonymous namespace
+
+Object InitRunScript(Env env) {
+  Object exports = Object::New(env);
+
+  exports["plainString"] = Function::New(env, RunPlainString);
+  exports["stdString"] = Function::New(env, RunStdString);
+  exports["jsString"] = Function::New(env, RunJsString);
+  exports["withContext"] = Function::New(env, RunWithContext);
+
+  return exports;
+}

test/run_script.js

@@ -0,0 +1,46 @@
+'use strict';
+const buildType = process.config.target_defaults.default_configuration;
+const assert = require('assert');
+const testUtil = require('./testUtil');
+
+test(require(`./build/${buildType}/binding.node`));
+test(require(`./build/${buildType}/binding_noexcept.node`));
+
+function test(binding) {
+  testUtil.runGCTests([
+    'Plain C string',
+    () => {
+      const sum = binding.run_script.plainString();
+      assert.strictEqual(sum, 1 + 2 + 3);
+    },
+
+    'std::string',
+    () => {
+      const sum = binding.run_script.stdString();
+      assert.strictEqual(sum, 1 + 2 + 3);
+    },
+
+    'JavaScript string',
+    () => {
+      const sum = binding.run_script.jsString("1 + 2 + 3");
+      assert.strictEqual(sum, 1 + 2 + 3);
+    },
+
+    'JavaScript, but not a string',
+    () => {
+      assert.throws(() => {
+        binding.run_script.jsString(true);
+      }, {
+        name: 'Error',
+        message: 'A string was expected'
+      });
+    },
+
+    'With context',
+    () => {
+      const a = 1, b = 2, c = 3;
+      const sum = binding.run_script.withContext("a + b + c", { a, b, c });
+      assert.strictEqual(sum, a + b + c);
+    }
+  ]);
+}