fix: parse variable references in unquoted strings

grammar.js

@@ -45,10 +45,12 @@ module.exports = grammar({
     comment: _ => /\#[^\n]*/,
 
     identifier: _ => /[A-Za-z_][A-Za-z0-9_]*/,
-    variable: $ => seq('$', choice(
+    variable: $ => choice(
-      $.identifier,
+      seq('$', $.identifier),
-      seq('{', $.identifier, '}')
+      $._braced_variable,
-    )),
+    ),
+
+    _braced_variable: $ => seq('$', '{', $.identifier, '}'),
 
     _value: $ => choice(
       $.string,
@@ -66,7 +68,35 @@ module.exports = grammar({
       $._unquoted_string,
     ),
 
-    _unquoted_string: $ => alias(/[^\#\s\"\'\$]+(?:[ \t]+[^\#\s\"\'\$]+)+/, $.string_content),
+    _unquoted_string: $ => choice(
+      alias($._unquoted_content, $.string_content),
+      seq(
+        choice(
+          alias($.value, $.string_content),
+          alias($.boolean, $.string_content),
+          alias($.decimal, $.string_content),
+          alias($.hexadecimal, $.string_content),
+          alias($.float, $.string_content),
+          alias($._unquoted_content, $.string_content),
+        ),
+        alias($._braced_variable, $.variable),
+        optional(choice(
+          alias($.value, $.string_content),
+          alias($._unquoted_content, $.string_content),
+        )),
+      ),
+    ),
+
+    _unquoted_content: _ => token(choice(
+      /[^\#\s\"\'\$]+(?:[ \t]+[^\#\s\"\'\$]+)+/,
+      seq(
+        /[^\#\s\"\'\$]+(?:[ \t]+[^\#\s\"\'\$]+)*/,
+        repeat1(seq(
+          /\$[A-Za-z_][A-Za-z0-9_]*/,
+          optional(/(?:[ \t]*[^\#\s\"\'\$]+)+/),
+        )),
+      ),
+    )),
 
     _literal_string: $ => seq(
       "'",

src/grammar.json

@@ -143,6 +143,28 @@
       "value": "[A-Za-z_][A-Za-z0-9_]*"
     },
     "variable": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "$"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "identifier"
+            }
+          ]
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_braced_variable"
+        }
+      ]
+    },
+    "_braced_variable": {
       "type": "SEQ",
       "members": [
         {
@@ -150,30 +172,16 @@
           "value": "$"
         },
         {
-          "type": "CHOICE",
+          "type": "STRING",
-          "members": [
+          "value": "{"
-            {
+        },
-              "type": "SYMBOL",
+        {
-              "name": "identifier"
+          "type": "SYMBOL",
-            },
+          "name": "identifier"
-            {
+        },
-              "type": "SEQ",
+        {
-              "members": [
+          "type": "STRING",
-                {
+          "value": "}"
-                  "type": "STRING",
-                  "value": "{"
-                },
-                {
-                  "type": "SYMBOL",
-                  "name": "identifier"
-                },
-                {
-                  "type": "STRING",
-                  "value": "}"
-                }
-              ]
-            }
-          ]
         }
       ]
     },
@@ -220,13 +228,167 @@
       ]
     },
     "_unquoted_string": {
-      "type": "ALIAS",
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "ALIAS",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_unquoted_content"
+          },
+          "named": true,
+          "value": "string_content"
+        },
+        {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "CHOICE",
+              "members": [
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "value"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                },
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "boolean"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                },
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "decimal"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                },
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "hexadecimal"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                },
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "float"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                },
+                {
+                  "type": "ALIAS",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "_unquoted_content"
+                  },
+                  "named": true,
+                  "value": "string_content"
+                }
+              ]
+            },
+            {
+              "type": "ALIAS",
+              "content": {
+                "type": "SYMBOL",
+                "name": "_braced_variable"
+              },
+              "named": true,
+              "value": "variable"
+            },
+            {
+              "type": "CHOICE",
+              "members": [
+                {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "ALIAS",
+                      "content": {
+                        "type": "SYMBOL",
+                        "name": "value"
+                      },
+                      "named": true,
+                      "value": "string_content"
+                    },
+                    {
+                      "type": "ALIAS",
+                      "content": {
+                        "type": "SYMBOL",
+                        "name": "_unquoted_content"
+                      },
+                      "named": true,
+                      "value": "string_content"
+                    }
+                  ]
+                },
+                {
+                  "type": "BLANK"
+                }
+              ]
+            }
+          ]
+        }
+      ]
+    },
+    "_unquoted_content": {
+      "type": "TOKEN",
       "content": {
-        "type": "PATTERN",
+        "type": "CHOICE",
-        "value": "[^\\#\\s\\\"\\'\\$]+(?:[ \\t]+[^\\#\\s\\\"\\'\\$]+)+"
+        "members": [
-      },
+          {
-      "named": true,
+            "type": "PATTERN",
-      "value": "string_content"
+            "value": "[^\\#\\s\\\"\\'\\$]+(?:[ \\t]+[^\\#\\s\\\"\\'\\$]+)+"
+          },
+          {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "PATTERN",
+                "value": "[^\\#\\s\\\"\\'\\$]+(?:[ \\t]+[^\\#\\s\\\"\\'\\$]+)*"
+              },
+              {
+                "type": "REPEAT1",
+                "content": {
+                  "type": "SEQ",
+                  "members": [
+                    {
+                      "type": "PATTERN",
+                      "value": "\\$[A-Za-z_][A-Za-z0-9_]*"
+                    },
+                    {
+                      "type": "CHOICE",
+                      "members": [
+                        {
+                          "type": "PATTERN",
+                          "value": "(?:[ \\t]*[^\\#\\s\\\"\\'\\$]+)+"
+                        },
+                        {
+                          "type": "BLANK"
+                        }
+                      ]
+                    }
+                  ]
+                }
+              }
+            ]
+          }
+        ]
+      }
     },
     "_literal_string": {
       "type": "SEQ",

test/corpus/scalar_interpolation.txt

@@ -0,0 +1,161 @@
+================================================================================
+Boolean prefixes become string content
+================================================================================
+
+PLAIN_TRUE=true
+TRUE_PREFIX=true${APP_NAME}
+PLAIN_FALSE=false
+FALSE_PREFIX=false${APP_NAME}
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment
+  (identifier)
+  (boolean))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (boolean))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier)))))
+
+================================================================================
+Numeric prefixes become string content
+================================================================================
+
+PLAIN_INTEGER=123
+INTEGER_PREFIX=123${APP_NAME}
+PLAIN_NEGATIVE=-123
+NEGATIVE_PREFIX=-123${APP_NAME}
+PLAIN_HEX=0xFF
+HEX_PREFIX=0xFF${APP_NAME}
+PLAIN_FLOAT=1.5
+FLOAT_PREFIX=1.5${APP_NAME}
+PLAIN_NEGATIVE_FLOAT=-1.5
+NEGATIVE_FLOAT_PREFIX=-1.5${APP_NAME}
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment
+  (identifier)
+  (number (integer (decimal))))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (number (integer (decimal))))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (number (integer (hexadecimal))))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (number (float)))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (number (float)))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier)))))
+
+================================================================================
+Scalar prefixes with suffixes and comments
+================================================================================
+
+BOOL=true${APP_NAME}-suffix # comment
+NUMBER=123${APP_NAME} suffix words
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))
+   (string_content)))
+ (comment)
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))
+   (string_content))))
+
+================================================================================
+Bare boolean-prefixed references are literal strings
+================================================================================
+
+BOOL=true$APP_NAME
+BOOL=false$APP_NAME
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content))))
+
+================================================================================
+Bare decimal-prefixed references are literal strings
+================================================================================
+
+NUMBER=123$APP_NAME
+NUMBER=-123$APP_NAME
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content))))
+
+================================================================================
+Bare hexadecimal-prefixed references are literal strings
+================================================================================
+
+HEX=0xFF$APP_NAME
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment (identifier) (string (string_content))))
+
+================================================================================
+Bare float-prefixed references are literal strings
+================================================================================
+
+FLOAT=1.5$APP_NAME
+FLOAT=-1.5$APP_NAME
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content))))

test/corpus/variables.txt

@@ -42,3 +42,85 @@ MULTIPLE = "variable is: ${VARIABLE}, and $ANOTHER !!!"
     (variable
      (identifier))
     (string_content))))
+
+================================================================================
+Unquoted braced variables with prefixes
+================================================================================
+
+BASIC = prefix${VARIABLE}
+VITE_APP_NAME=xxx${APP_NAME}
+SUFFIX = prefix${VARIABLE}-suffix
+MULTIWORD = prefix words${VARIABLE} suffix words # comment
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment
+  key: (identifier)
+  value: (string
+   (string_content)
+   (variable
+    (identifier))))
+ (assignment
+  key: (identifier)
+  value: (string
+   (string_content)
+   (variable
+    (identifier))))
+ (assignment
+  key: (identifier)
+  value: (string
+   (string_content)
+   (variable
+    (identifier))
+   (string_content)))
+ (assignment
+  key: (identifier)
+  value: (string
+   (string_content)
+   (variable
+    (identifier))
+   (string_content)))
+ (comment))
+
+================================================================================
+Unquoted bare references with prefixes are literal strings
+================================================================================
+
+VITE_APP_NAME=xxx$APP_NAME
+NAME=XXX$APP_NAME
+SUFFIX=xxx$APP_NAME-suffix
+MULTIPLE=xxx$APP_NAME$OTHER
+MULTIWORD=prefix words$APP_NAME suffix words # comment
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content)))
+ (assignment (identifier) (string (string_content)))
+ (comment))
+
+================================================================================
+Literal bare references alongside braced interpolation
+================================================================================
+
+PREFIX=xxx$LITERAL${APP_NAME}
+SUFFIX=xxx${APP_NAME}suffix$LITERAL
+
+--------------------------------------------------------------------------------
+
+(document
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))))
+ (assignment
+  (identifier)
+  (string
+   (string_content)
+   (variable (identifier))
+   (string_content))))