clang-format: [JS] do not wrap after `asserts`

[mprobst]

Summary

asserts is a pseudo keyword in TypeScript used in return types.
Wrapping after it triggers automatic semicolon insertion, which
breaks the code semantics/syntax.

asserts is different from other pseudo keywords in that it is
specific to TS and only carries meaning in a very specific location.
Thus introducing a token type is probably overkill.

[h-joo]

clang/lib/Format/TokenAnnotator.cpp

3856

Not for this PR : The JS specific part of the code is growing, please consider splitting it

[h-joo]

clang/lib/Format/TokenAnnotator.cpp

3856

(..into a function)

clang/lib/Format/TokenAnnotator.cpp

if (NonComment &&
             Keywords.kw_readonly, Keywords.kw_abstract, Keywords.kw_get,
             Keywords.kw_set, Keywords.kw_async, Keywords.kw_await))
       return false; // Otherwise automatic semicolon insertion would trigger.
     if (Right.NestingLevel == 0 &&
         (Left.Tok.getIdentifierInfo() ||
          Left.isOneOf(tok::r_square, tok::r_paren)) &&
         Right.isOneOf(tok::l_square, tok::l_paren))
       return false; // Otherwise automatic semicolon insertion would trigger.
+    if (NonComment && NonComment->is(tok::identifier) &&
+        NonComment->TokenText == "asserts")
+      return false;
     if (Left.is(TT_JsFatArrow) && Right.is(tok::l_brace))
       return false;
     if (Left.is(TT_JsTypeColon))
       return true;
     // Don't wrap between ":" and "!" of a strict prop init ("field!: type;").
     if (Left.is(tok::exclaim) && Right.is(tok::colon))
       return false;
     // Look for is type annotations like:

clang/unittests/Format/FormatTestJS.cpp

 
 TEST_F(FormatTestJS, DeclaredFields) {
   verifyFormat("class Example {\n"
                "  declare pub: string;\n"
                "  declare private priv: string;\n"
                "}\n");
 }
 
+TEST_F(FormatTestJS, NoBreakAfterAsserts) {
+  verifyFormat(
+      "interface Assertable<State extends {}> {\n"
+      "  assert<ExportedState extends {}, DependencyState extends State = "
+      "State>(\n"
+      "      callback: Callback<ExportedState, DependencyState>):\n"
+      "      asserts this is ExtendedState<DependencyState&ExportedState>;\n"
+      "}\n",
+      "interface Assertable<State extends {}> {\n"
+      "  assert<ExportedState extends {}, DependencyState extends State = "
+      "State>(callback: Callback<ExportedState, DependencyState>): asserts "
+      "this is ExtendedState<DependencyState&ExportedState>;\n"
+      "}\n");
+}
+
 } // namespace format
 } // end namespace clang