Merge pull request #517 from bkeepers/refactor

Refactor parser to avoid duplicate scan/gsub

lib/dotenv/parser.rb

@@ -8,25 +8,29 @@ class FormatError < SyntaxError; end
   # Parses the `.env` file format into key/value pairs.
   # It allows for variable substitutions, command substitutions, and exporting of variables.
   class Parser
-    @substitutions =
-      [Dotenv::Substitutions::Variable, Dotenv::Substitutions::Command]
+    @substitutions = [
+      Dotenv::Substitutions::Variable,
+      Dotenv::Substitutions::Command
+    ]
 
     LINE = /
-      (?:^|\A)              # beginning of line
-      \s*                   # leading whitespace
-      (?:export\s+)?        # optional export
-      ([\w.]+)              # key
-      (?:\s*=\s*?|:\s+?)    # separator
-      (                     # optional value begin
-        \s*'(?:\\'|[^'])*'  #   single quoted value
-        |                   #   or
-        \s*"(?:\\"|[^"])*"  #   double quoted value
-        |                   #   or
-        [^\#\r\n]+          #   unquoted value
-      )?                    # value end
-      \s*                   # trailing whitespace
-      (?:\#.*)?             # optional comment
-      (?:$|\z)              # end of line
+      (?:^|\A)                # beginning of line
+      \s*                     # leading whitespace
+      (?<export>export\s+)?   # optional export
+      (?<key>[\w.]+)          # key
+      (?:                     # optional separator and value
+        (?:\s*=\s*?|:\s+?)    #   separator
+        (?<value>             #   optional value begin
+          \s*'(?:\\'|[^'])*'  #     single quoted value
+          |                   #     or
+          \s*"(?:\\"|[^"])*"  #     double quoted value
+          |                   #     or
+          [^\#\n]+            #     unquoted value
+        )?                    #   value end
+      )?                      # separator and value end
+      \s*                     # trailing whitespace
+      (?:\#.*)?               # optional comment
+      (?:$|\z)                # end of line
     /x
 
     class << self
@@ -38,43 +42,55 @@ def call(...)
     end
 
     def initialize(string, overwrite: false)
-      @string = string
+      # Convert line breaks to same format
+      @string = string.gsub(/[\n\r]+/, "\n")
       @hash = {}
-      @variables_to_ignore = overwrite ? nil : ENV.except("DOTENV_LINEBREAK_MODE")
+      @overwrite = overwrite
     end
 
     def call
-      # Convert line breaks to same format
-      lines = @string.gsub(/\r\n?/, "\n")
-      # Process matches
-      lines.scan(LINE).each do |key, value|
-        next if @variables_to_ignore&.include?(key)
-
-        @hash[key] = parse_value(value || "")
-      end
-      # Process non-matches
-      lines.gsub(LINE, "").split(/[\n\r]+/).each do |line|
-        parse_line(line)
+      @string.scan(LINE) do
+        match = $LAST_MATCH_INFO
+
+        # Skip parsing values that will be ignored
+        next if ignore?(match[:key])
+
+        # Check for exported variable with no value
+        if match[:export] && !match[:value]
+          if !@hash.member?(match[:key])
+            raise FormatError, "Line #{match.to_s.inspect} has an unset variable"
+          end
+        else
+          @hash[match[:key]] = parse_value(match[:value] || "")
+        end
       end
+
       @hash
     end
 
     private
 
-    def parse_line(line)
-      if line.split.first == "export"
-        if variable_not_set?(line)
-          raise FormatError, "Line #{line.inspect} has an unset variable"
-        end
-      end
+    # Determine if the key can be ignored.
+    def ignore?(key)
+      !@overwrite && key != "DOTENV_LINEBREAK_MODE" && ENV.key?(key)
     end
 
+    QUOTED_STRING = /\A(['"])(.*)\1\z/m
     def parse_value(value)
       # Remove surrounding quotes
-      value = value.strip.sub(/\A(['"])(.*)\1\z/m, '\2')
+      value = value.strip.sub(QUOTED_STRING, '\2')
       maybe_quote = Regexp.last_match(1)
-      value = unescape_value(value, maybe_quote)
-      perform_substitutions(value, maybe_quote)
+
+      # Expand new lines in double quoted values
+      value = expand_newlines(value) if maybe_quote == '"'
+
+      # Unescape characters and performs substitutions unless value is single quoted
+      if maybe_quote != "'"
+        value = unescape_characters(value)
+        self.class.substitutions.each { |proc| value = proc.call(value, @hash) }
+      end
+
+      value
     end
 
     def unescape_characters(value)
@@ -88,28 +104,5 @@ def expand_newlines(value)
         value.gsub('\n', "\\\\\\n").gsub('\r', "\\\\\\r")
       end
     end
-
-    def variable_not_set?(line)
-      !line.split[1..].all? { |var| @hash.member?(var) }
-    end
-
-    def unescape_value(value, maybe_quote)
-      if maybe_quote == '"'
-        unescape_characters(expand_newlines(value))
-      elsif maybe_quote.nil?
-        unescape_characters(value)
-      else
-        value
-      end
-    end
-
-    def perform_substitutions(value, maybe_quote)
-      if maybe_quote != "'"
-        self.class.substitutions.each do |proc|
-          value = proc.call(value, @hash)
-        end
-      end
-      value
-    end
   end
 end

lib/dotenv/substitutions/variable.rb

@@ -12,7 +12,7 @@ class << self
         VARIABLE = /
           (\\)?         # is it escaped with a backslash?
           (\$)          # literal $
-          (?!\()        # shouldnt be followed by paranthesis
+          (?!\()        # shouldn't be followed by parenthesis
           \{?           # allow brace wrapping
           ([A-Z0-9_]+)? # optional alpha nums
           \}?           # closing brace
@@ -21,19 +21,14 @@ class << self
         def call(value, env)
           value.gsub(VARIABLE) do |variable|
             match = $LAST_MATCH_INFO
-            substitute(match, variable, env)
-          end
-        end
-
-        private
 
-        def substitute(match, variable, env)
-          if match[1] == "\\"
-            variable[1..]
-          elsif match[3]
-            env[match[3]] || ENV[match[3]] || ""
-          else
-            variable
+            if match[1] == "\\"
+              variable[1..]
+            elsif match[3]
+              env[match[3]] || ENV[match[3]] || ""
+            else
+              variable
+            end
           end
         end
       end

lib/dotenv/template.rb

@@ -34,7 +34,7 @@ def is_comment?(line)
 
     def var_defined?(line)
       match = Dotenv::Parser::LINE.match(line)
-      match && match[1]
+      match && match[:key]
     end
 
     def line_blank?(line)