xref: /aosp_15_r20/external/pdfium/fxjs/cjs_result.h (revision 3ac0a46f773bac49fa9476ec2b1cf3f8da5ec3a4)
1 // Copyright 2017 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #ifndef FXJS_CJS_RESULT_H_
8 #define FXJS_CJS_RESULT_H_
9 
10 #include "fxjs/js_resources.h"
11 #include "third_party/abseil-cpp/absl/types/optional.h"
12 #include "v8/include/v8-forward.h"
13 
14 class CJS_Result {
15  public:
16   // Wrap constructors with static methods so we can apply [[nodiscard]],
17   // otherwise we can't catch places where someone mistakenly writes:
18   //
19   //     if (error)
20   //       CJS_Result(JS_ERROR_CODE);
21   //
22   // instead of
23   //
24   //     if (error)
25   //       return CJS_Result(JS_ERROR_CODE);
26   //
Success()27   [[nodiscard]] static CJS_Result Success() { return CJS_Result(); }
Success(v8::Local<v8::Value> value)28   [[nodiscard]] static CJS_Result Success(v8::Local<v8::Value> value) {
29     return CJS_Result(value);
30   }
Failure(const WideString & str)31   [[nodiscard]] static CJS_Result Failure(const WideString& str) {
32     return CJS_Result(str);
33   }
Failure(JSMessage id)34   [[nodiscard]] static CJS_Result Failure(JSMessage id) {
35     return CJS_Result(id);
36   }
37 
38   CJS_Result(const CJS_Result&);
39   ~CJS_Result();
40 
HasError()41   bool HasError() const { return error_.has_value(); }
Error()42   const WideString& Error() const { return error_.value(); }
43 
HasReturn()44   bool HasReturn() const { return !return_.IsEmpty(); }
Return()45   v8::Local<v8::Value> Return() const { return return_; }
46 
47  private:
48   CJS_Result();                               // Successful but empty return.
49   explicit CJS_Result(v8::Local<v8::Value>);  // Successful return with value.
50   explicit CJS_Result(const WideString&);     // Error with custom message.
51   explicit CJS_Result(JSMessage id);          // Error with stock message.
52 
53   absl::optional<WideString> error_;
54   v8::Local<v8::Value> return_;
55 };
56 
57 #endif  // FXJS_CJS_RESULT_H_
58