Class: ImportJS::ImportStatement

Inherits:
Object
  • Object
show all
Defined in:
lib/import_js/import_statement.rb

Overview

Class that represents an import statement, e.g. ‘const foo = require(’foo’);‘ `let foo = myCustomRequire(’foo’);‘ `import foo from ’foo’;‘

Constant Summary collapse

REGEX_CONST_LET_VAR = 
/
  \A
  (?<declaration_keyword>const|let|var)\s+ # <declaration_keyword>
  (?<assignment>.+?)   # <assignment> variable assignment
  \s*=\s*
  (?<import_function>[^\(]+?)\( # <import_function> variable assignment
    (?<quote>'|")      # <quote> opening quote
    (?<path>[^\2]+)    # <path> module path
    \k<quote>          # closing quote
  \);?
  \s*
/xm
REGEX_IMPORT = 
/
  \A
  (?<declaration_keyword>import)\s+ # <declaration_keyword>
  (?<assignment>.*?) # <assignment> variable assignment
  \s+from\s+
  (?<quote>'|")      # <quote> opening quote
  (?<path>[^\2]+)    # <path> module path
  \k<quote>          # closing quote
  ;?\s*
/xm
REGEX_NAMED = 
/
  (?:                # non-capturing group
    (?<default>.*?)  # <default> default import
    ,\s*
  )?
  \{
    \s*
    (?<named>.*)      # <named> named imports
    \s*
  \}
/xm

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#assignment ⇒ Object

Returns the value of attribute assignment.



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# File 'lib/import_js/import_statement.rb', line 43

def assignment
  @assignment
end

#declaration_keyword ⇒ Object

Returns the value of attribute declaration_keyword.



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# File 'lib/import_js/import_statement.rb', line 44

def declaration_keyword
  @declaration_keyword
end

#default_import ⇒ Object

Returns the value of attribute default_import.



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# File 'lib/import_js/import_statement.rb', line 45

def default_import
  @default_import
end

#import_function ⇒ Object

Returns the value of attribute import_function.



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# File 'lib/import_js/import_statement.rb', line 47

def import_function
  @import_function
end

#named_imports ⇒ Object

Returns the value of attribute named_imports.



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# File 'lib/import_js/import_statement.rb', line 46

def named_imports
  @named_imports
end

#original_import_string ⇒ Object

a cache of the parsed import string



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# File 'lib/import_js/import_statement.rb', line 48

def original_import_string
  @original_import_string
end

#path ⇒ Object

Returns the value of attribute path.



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# File 'lib/import_js/import_statement.rb', line 49

def path
  @path
end

Class Method Details

.parse(string) ⇒ ImportJS::ImportStatement?

Returns a parsed statement, or nil if the string can’t be parsed.

Parameters:

  • string (String) —

    a possible import statement, e.g. ‘const foo = require(’foo’);‘ `let foo = myCustomRequire(’foo’);‘ `import foo from ’foo’;‘

Returns:



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# File 'lib/import_js/import_statement.rb', line 57

def self.parse(string)
  match = REGEX_CONST_LET_VAR.match(string) ||
          REGEX_IMPORT.match(string)
  return unless match

  statement = new
  statement.original_import_string = match.string
  statement.declaration_keyword = match[:declaration_keyword]
  statement.path = match[:path]
  statement.assignment = match[:assignment]
  if match.names.include? 'import_function'
    statement.import_function = match[:import_function]
  end
  dest_match = statement.assignment.match(REGEX_NAMED)
  if dest_match
    statement.default_import = dest_match[:default]
    statement.named_imports =
      dest_match[:named].split(/,\s*/).map(&:strip)
  else
    statement.default_import = statement.assignment
  end
  statement
end

Instance Method Details

#delete_variable(variable_name) ⇒ Object

Deletes a variable from an already existing default import or set of

named imports.

Parameters:

  • variable_name (String) 


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# File 'lib/import_js/import_statement.rb', line 101

def delete_variable(variable_name)
  @default_import = nil if default_import == variable_name
  @named_imports.delete(variable_name) if named_imports?

  clear_import_string_cache
end

#empty? ⇒ Boolean

Returns true if there is no default import and there are no named imports.

Returns:

  • (Boolean) —

    true if there is no default import and there are no named imports



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# File 'lib/import_js/import_statement.rb', line 115

def empty?
  default_import.nil? && !named_imports?
end

#inject_named_import(variable_name) ⇒ Object

Injects a new variable into an already existing set of named imports.

Parameters:

  • variable_name (String) 


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# File 'lib/import_js/import_statement.rb', line 90

def inject_named_import(variable_name)
  @named_imports ||= []
  named_imports << variable_name
  named_imports.sort!.uniq!

  clear_import_string_cache
end

#merge(import_statement) ⇒ Object

Merge another ImportStatement into this one.

Parameters:



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# File 'lib/import_js/import_statement.rb', line 158

def merge(import_statement)
  if import_statement.default_import
    @default_import = import_statement.default_import
    clear_import_string_cache
  end

  if import_statement.named_imports?
    @named_imports ||= []
    @named_imports.concat(import_statement.named_imports)
    @named_imports.sort!.uniq!
    clear_import_string_cache
  end
end

#named_imports? ⇒ Boolean

Returns true if there are named imports.

Returns:

  • (Boolean) —

    true if there are named imports



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# File 'lib/import_js/import_statement.rb', line 109

def named_imports?
  !named_imports.nil? && !named_imports.empty?
end

#set_default_import(value) ⇒ Object

Sets the default_import and clears the original import string cache.

Parameters:

  • value (String) 


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# File 'lib/import_js/import_statement.rb', line 83

def set_default_import(value)
  @default_import = value
  clear_import_string_cache
end

#to_import_strings(max_line_length, tab) ⇒ Array

Returns generated import statement strings.

Parameters:

  • max_line_length (Number) —

    where to cap lines at

  • tab (String) —

    e.g. ‘ ’ (two spaces)

Returns:

  • (Array) —

    generated import statement strings



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# File 'lib/import_js/import_statement.rb', line 130

def to_import_strings(max_line_length, tab)
  return [original_import_string] if original_import_string

  if declaration_keyword == 'import'
    # ES2015 Modules (ESM) syntax can support default imports and
    # named imports on the same line.
    if named_imports?
      [named_import_string(max_line_length, tab)]
    else
      [default_import_string(max_line_length, tab)]
    end
  else # const/let/var
    strings = []

    if default_import
      strings << default_import_string(max_line_length, tab)
    end

    if named_imports?
      strings << named_import_string(max_line_length, tab)
    end

    strings
  end
end

#to_normalized ⇒ Array

Returns an array that can be used in ‘uniq!` to dedupe equal statements, e.g. `const foo = require(’foo’);‘ `import foo from ’foo’;‘.

Returns:

  • (Array) —

    an array that can be used in ‘uniq!` to dedupe equal statements, e.g. `const foo = require(’foo’);‘ `import foo from ’foo’;‘



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# File 'lib/import_js/import_statement.rb', line 123

def to_normalized
  [default_import, named_imports, path]
end