Add support for optional chaining operator to TypeScript lexer (rouge…

…-ruby#1475) TypeScript has added support for the optional chaining operator `?.` as of version 3.7. This commit adds support by prepending a rule to the `:root` state of the TypeScript lexer. Eventually, when JavaScript adopts the operator, the rule should be moved into the `:root` state there and removed from this lexer.
NSHipster · May 21, 2020 · b2848b3 · b2848b3
1 parent bf871c6
commit b2848b3
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diff --git a/lib/rouge/lexers/typescript.rb b/lib/rouge/lexers/typescript.rb
@@ -19,6 +19,10 @@ class Typescript < Javascript
 
       mimetypes 'text/typescript'
 
+      prepend :root do
+        rule %r/[?][.]/, Punctuation
+      end
+
       prepend :statement do
         rule %r/(#{Javascript.id_regex})(\??)(\s*)(:)/ do
           groups Name::Label, Punctuation, Text, Punctuation

diff --git a/spec/visual/samples/typescript b/spec/visual/samples/typescript
@@ -198,3 +198,8 @@ declare module "foo" {
     [K in keyof IFoo]?: IFoo[K]
   }
 }
+
+// Template strings
+const x = `Hello world ${a.b}`;
+const y = `Hello world ${a?.b}`;
+const z = `Hello world`;