Handle EOF in hash pattern key

snapshots/pattern_one_line_bare_key.txt

@@ -0,0 +1,62 @@
+@ ProgramNode (location: (1,0)-(1,15))
+├── flags: ∅
+├── locals: [:b]
+└── statements:
+    @ StatementsNode (location: (1,0)-(1,15))
+    ├── flags: ∅
+    └── body: (length: 1)
+        └── @ MatchRequiredNode (location: (1,0)-(1,15))
+            ├── flags: newline
+            ├── value:
+            │   @ CallNode (location: (1,0)-(1,3))
+            │   ├── flags: variable_call, ignore_visibility
+            │   ├── receiver: ∅
+            │   ├── call_operator_loc: ∅
+            │   ├── name: :foo
+            │   ├── message_loc: (1,0)-(1,3) = "foo"
+            │   ├── opening_loc: ∅
+            │   ├── arguments: ∅
+            │   ├── closing_loc: ∅
+            │   ├── equal_loc: ∅
+            │   └── block: ∅
+            ├── pattern:
+            │   @ HashPatternNode (location: (1,7)-(1,15))
+            │   ├── flags: ∅
+            │   ├── constant: ∅
+            │   ├── elements: (length: 2)
+            │   │   ├── @ AssocNode (location: (1,7)-(1,11))
+            │   │   │   ├── flags: static_literal
+            │   │   │   ├── key:
+            │   │   │   │   @ SymbolNode (location: (1,7)-(1,9))
+            │   │   │   │   ├── flags: static_literal, forced_us_ascii_encoding
+            │   │   │   │   ├── opening_loc: ∅
+            │   │   │   │   ├── value_loc: (1,7)-(1,8) = "a"
+            │   │   │   │   ├── closing_loc: (1,8)-(1,9) = ":"
+            │   │   │   │   └── unescaped: "a"
+            │   │   │   ├── value:
+            │   │   │   │   @ IntegerNode (location: (1,10)-(1,11))
+            │   │   │   │   ├── flags: static_literal, decimal
+            │   │   │   │   └── value: 1
+            │   │   │   └── operator_loc: ∅
+            │   │   └── @ AssocNode (location: (1,13)-(1,15))
+            │   │       ├── flags: ∅
+            │   │       ├── key:
+            │   │       │   @ SymbolNode (location: (1,13)-(1,15))
+            │   │       │   ├── flags: static_literal, forced_us_ascii_encoding
+            │   │       │   ├── opening_loc: ∅
+            │   │       │   ├── value_loc: (1,13)-(1,14) = "b"
+            │   │       │   ├── closing_loc: (1,14)-(1,15) = ":"
+            │   │       │   └── unescaped: "b"
+            │   │       ├── value:
+            │   │       │   @ ImplicitNode (location: (1,13)-(1,14))
+            │   │       │   ├── flags: ∅
+            │   │       │   └── value:
+            │   │       │       @ LocalVariableTargetNode (location: (1,13)-(1,14))
+            │   │       │       ├── flags: ∅
+            │   │       │       ├── name: :b
+            │   │       │       └── depth: 0
+            │   │       └── operator_loc: ∅
+            │   ├── rest: ∅
+            │   ├── opening_loc: ∅
+            │   └── closing_loc: ∅
+            └── operator_loc: (1,4)-(1,6) = "=>"

src/prism.c

@@ -16907,7 +16907,7 @@ parse_pattern_hash(pm_parser_t *parser, pm_constant_id_list_t *captures, pm_node
             parse_pattern_hash_key(parser, &keys, key);
             pm_node_t *value = NULL;
 
-            if (match7(parser, PM_TOKEN_COMMA, PM_TOKEN_KEYWORD_THEN, PM_TOKEN_BRACE_RIGHT, PM_TOKEN_BRACKET_RIGHT, PM_TOKEN_PARENTHESIS_RIGHT, PM_TOKEN_NEWLINE, PM_TOKEN_SEMICOLON)) {
+            if (match8(parser, PM_TOKEN_COMMA, PM_TOKEN_KEYWORD_THEN, PM_TOKEN_BRACE_RIGHT, PM_TOKEN_BRACKET_RIGHT, PM_TOKEN_PARENTHESIS_RIGHT, PM_TOKEN_NEWLINE, PM_TOKEN_SEMICOLON, PM_TOKEN_EOF)) {
                 if (PM_NODE_TYPE_P(key, PM_SYMBOL_NODE)) {
                     value = parse_pattern_hash_implicit_value(parser, captures, (pm_symbol_node_t *) key);
                 } else {

test/prism/errors/pattern_string_key.txt

@@ -2,7 +2,6 @@ case:a
 ^~~~ expected an `end` to close the `case` statement
 in b:"","#{}"
         ^~~~~ expected a label after the `,` in the hash pattern
-             ^ expected a pattern expression after the key
              ^ expected a delimiter after the patterns of an `in` clause
              ^ unexpected end-of-input, assuming it is closing the parent top level context
 

test/prism/fixtures/pattern_one_line_bare_key.txt

@@ -0,0 +1 @@
+foo => a: 1, b: