Handle newlines after pair-keys

Author: aibaars

grammar.js

@@ -36,6 +36,7 @@ module.exports = grammar({
   inline: $ => [$._arg_rhs, $._call_operator],
   externals: $ => [
     $._line_break,
+    $._no_line_break,
 
     // Delimited literals
     $.simple_symbol,
@@ -1177,7 +1178,12 @@ module.exports = grammar({
           alias($.constant_suffix, $.hash_key_symbol),
         )),
         token.immediate(':'),
-        field('value', optional($._arg))
+        choice(
+          field('value', optional($._arg)),
+          // This alternative never matches, because '_no_line_break' tokens do not exist.
+          // The purpose is give a hint to the scanner that it should not produce any line-break
+          // terminators at this point.
+          $._no_line_break)
       )
     )),
 

src/grammar.json

@@ -7695,20 +7695,29 @@
                 }
               },
               {
-                "type": "FIELD",
-                "name": "value",
-                "content": {
-                  "type": "CHOICE",
-                  "members": [
-                    {
-                      "type": "SYMBOL",
-                      "name": "_arg"
-                    },
-                    {
-                      "type": "BLANK"
+                "type": "CHOICE",
+                "members": [
+                  {
+                    "type": "FIELD",
+                    "name": "value",
+                    "content": {
+                      "type": "CHOICE",
+                      "members": [
+                        {
+                          "type": "SYMBOL",
+                          "name": "_arg"
+                        },
+                        {
+                          "type": "BLANK"
+                        }
+                      ]
                     }
-                  ]
-                }
+                  },
+                  {
+                    "type": "SYMBOL",
+                    "name": "_no_line_break"
+                  }
+                ]
               }
             ]
           }
@@ -7823,6 +7832,10 @@
       "type": "SYMBOL",
       "name": "_line_break"
     },
+    {
+      "type": "SYMBOL",
+      "name": "_no_line_break"
+    },
     {
       "type": "SYMBOL",
       "name": "simple_symbol"