clang-format: [JS] post-fix non-null assertion operator.

[mprobst]

Summary

Do not insert whitespace preceding the "!" postfix operator. This is an
incomplete fix, but should cover common usage.

[djasper]

lib/Format/TokenAnnotator.cpp

2127 ↗

(On Diff #60242)

From a quick look at our codebase, I think you need to also rule out the following for Right.Next:

• (, [, {
• ! ('!!' seems to be a thing)
• -, +, ~ (don't know exactly what this does to a JS boolean value)
• %, $ (not entirely sure whether these become part of the identifier)

[mprobst]

• invert check to whitelist known tokens that can precede a non-null assertion.

lib/Format/TokenAnnotator.cpp

2127 ↗

(On Diff #60242)

Actually, I think inverting the condition and "whitelisting" preceding tokens makes more sense and is probably a lot more robust. PTAL, now checking left for identifier, r_paren, r_square, literal.

[djasper]

lib/Format/TokenAnnotator.cpp

2128 ↗

(On Diff #60308)

Can you add a test for each of these? Also, how can a literal be null?

[mprobst]

• more tests

lib/Format/TokenAnnotator.cpp

2128 ↗

(On Diff #60311)

Tests added. A literal cannot really be null, but the operator is allowed after any kind of expression, and it's straight forward to test for it here.

cfe/trunk/lib/Format/TokenAnnotator.cpp

if (Left.is(tok::ellipsis))
       return false;
     if (Left.is(TT_TemplateCloser) &&
         !Right.isOneOf(tok::equal, tok::l_brace, tok::comma, tok::l_square,
                        Keywords.kw_implements, Keywords.kw_extends))
       // Type assertions ('<type>expr') are not followed by whitespace. Other
       // locations that should have whitespace following are identified by the
       // above set of follower tokens.
       return false;
+    // Postfix non-null assertion operator, as in `foo!.bar()`.
+    if (Right.is(tok::exclaim) && (Left.isOneOf(tok::identifier, tok::r_paren,
+                                                tok::r_square, tok::r_brace) ||
+                                   Left.Tok.isLiteral()))
+      return false;
   } else if (Style.Language == FormatStyle::LK_Java) {
     if (Left.is(tok::r_square) && Right.is(tok::l_brace))
       return true;
     if (Left.is(Keywords.kw_synchronized) && Right.is(tok::l_paren))
       return Style.SpaceBeforeParens != FormatStyle::SBPO_Never;
     if ((Left.isOneOf(tok::kw_static, tok::kw_public, tok::kw_private,
                       tok::kw_protected) ||
          Left.isOneOf(Keywords.kw_final, Keywords.kw_abstract,

cfe/trunk/unittests/Format/FormatTestJS.cpp

 
 TEST_F(FormatTestJS, SupportShebangLines) {
   verifyFormat("#!/usr/bin/env node\n"
                "var x = hello();",
                "#!/usr/bin/env node\n"
                "var x   =  hello();");
 }
 
+TEST_F(FormatTestJS, NonNullAssertionOperator) {
+  verifyFormat("let x = foo!.bar();\n");
+  verifyFormat("let x = foo ? bar! : baz;\n");
+  verifyFormat("let x = !foo;\n");
+  verifyFormat("let x = foo[0]!;\n");
+  verifyFormat("let x = (foo)!;\n");
+  verifyFormat("let x = {foo: 1}!;\n");
+}
+
 } // end namespace tooling
 } // end namespace clang