Commit a7638d38 authored by Martin Probst's avatar Martin Probst
Browse files

clang-format: [JS] support null operators. 

Summary:
JavaScript / TypeScript is adding two new operators: the null
propagating operator `?.` and the nullish coalescing operator `??`.

    const x = foo ?? 'default';
    const z = foo?.bar?.baz;

This change adds support to lex and format both.

Reviewers: krasimir

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69971
parent 48b7068b

clang/lib/Format/FormatToken.h

+2 −0
Original line number Diff line number Diff line
@@ -60,6 +60,8 @@ namespace format { 
  TYPE(JsExponentiationEqual)                                                  \

  TYPE(JsFatArrow)                                                             \

  TYPE(JsNonNullAssertion)                                                     \

  TYPE(JsNullishCoalescingOperator)                                            \

  TYPE(JsNullPropagatingOperator)                                              \

  TYPE(JsPrivateIdentifier)                                                    \

  TYPE(JsTypeColon)                                                            \

  TYPE(JsTypeOperator)                                                         \

clang/lib/Format/FormatTokenLexer.cpp

+12 −0
Original line number Diff line number Diff line
@@ -100,6 +100,10 @@ void FormatTokenLexer::tryMergePreviousTokens() { 
    static const tok::TokenKind JSExponentiation[] = {tok::star, tok::star};

    static const tok::TokenKind JSExponentiationEqual[] = {tok::star,

                                                           tok::starequal};

    static const tok::TokenKind JSNullPropagatingOperator[] = {tok::question,

                                                               tok::period};

    static const tok::TokenKind JSNullishOperator[] = {tok::question,

                                                       tok::question};



    // FIXME: Investigate what token type gives the correct operator priority.

    if (tryMergeTokens(JSIdentity, TT_BinaryOperator))
@@ -116,6 +120,14 @@ void FormatTokenLexer::tryMergePreviousTokens() { 
      Tokens.back()->Tok.setKind(tok::starequal);

      return;

    }

    if (tryMergeTokens(JSNullishOperator, TT_JsNullishCoalescingOperator))

      return;

    if (tryMergeTokens(JSNullPropagatingOperator,

                       TT_JsNullPropagatingOperator)) {

      // Treat like a regular "." access.

      Tokens.back()->Tok.setKind(tok::period);

      return;

    }

    if (tryMergeJSPrivateIdentifier())

      return;

  }

clang/unittests/Format/FormatTestJS.cpp

+10 −0
Original line number Diff line number Diff line
@@ -2222,6 +2222,16 @@ TEST_F(FormatTestJS, NonNullAssertionOperator) { 
  verifyFormat("return !!x;\n");

}



TEST_F(FormatTestJS, NullPropagatingOperator) {

  verifyFormat("let x = foo?.bar?.baz();\n");

  verifyFormat("let x = foo?.(foo);\n");

  verifyFormat("let x = foo?.['arr'];\n");

}



TEST_F(FormatTestJS, NullishCoalescingOperator) {

  verifyFormat("const val = something ?? 'some other default';\n");

}



TEST_F(FormatTestJS, Conditional) {

  verifyFormat("y = x ? 1 : 2;");

  verifyFormat("x ? 1 : 2;");