generators.rb in prop_check-0.11.0

- old
+ new

@@ -225,34 +225,60 @@
     ##
     # Generates an array of elements, where each of the elements
     # is generated by `element_generator`.
     #
     # Shrinks to shorter arrays (with shrunken elements).
+    # Accepted keyword arguments:
     #
+    # `empty:` When false, behaves the same as `min: 1`
+    # `min:` Ensures at least this many elements are generated. (default: 0)
+    # `max:` Ensures at most this many elements are generated. When nil, an arbitrary count is used instead. (default: nil)
+    #
+    #
+    #    >> Generators.array(Generators.positive_integer).sample(5, size: 1, rng: Random.new(42))
+    #    =>  [[2], [2], [2], [1], [2]]
     #    >> Generators.array(Generators.positive_integer).sample(5, size: 10, rng: Random.new(42))
     #    => [[10, 5, 1, 4], [5, 9, 1, 1, 11, 8, 4, 9, 11, 10], [6], [11, 11, 2, 2, 7, 2, 6, 5, 5], [2, 10, 9, 7, 9, 5, 11, 3]]
-    def array(element_generator)
-      nonnegative_integer.bind do |generator|
-        generators = (0...generator).map do
+    #
+    #    >> Generators.array(Generators.positive_integer, empty: true).sample(5, size: 1, rng: Random.new(1))
+    #    =>  [[], [2], [], [], [2]]
+    #    >> Generators.array(Generators.positive_integer, empty: false).sample(5, size: 1, rng: Random.new(1))
+    #    =>  [[2], [1], [2], [1], [1]]
+
+
+    def array(element_generator, min: 0, max: nil, empty: true)
+      min = 1 if min.zero? && !empty
+
+      res = proc do |count|
+        count = min + 1 if count < min
+        count += 1 if count == min && min != 0
+        generators = (min...count).map do
           element_generator.clone
         end
 
         tuple(*generators)
       end
+
+      if max.nil?
+        nonnegative_integer.bind(&res)
+      else
+        proc.call(max)
+      end
     end
 
+
     ##
     # Generates a hash of key->values,
     # where each of the keys is made using the `key_generator`
     # and each of the values using the `value_generator`.
     #
     # Shrinks to hashes with less key/value pairs.
     #
     #    >> Generators.hash(Generators.printable_ascii_string, Generators.positive_integer).sample(5, size: 3, rng: Random.new(42))
     #    => [{""=>2, "g\\4"=>4, "rv"=>2}, {"7"=>2}, {"!"=>1, "E!"=>1}, {"kY5"=>2}, {}]
-    def hash(key_generator, value_generator)
-      array(tuple(key_generator, value_generator))
+    def hash(key_generator, value_generator, **kwargs)
+      array(tuple(key_generator, value_generator), **kwargs)
         .map(&:to_h)
     end
 
 
     @alphanumeric_chars = [('a'..'z'), ('A'..'Z'), ('0'..'9')].flat_map(&:to_a).freeze
@@ -274,12 +300,12 @@
     #
     # Shrinks towards fewer characters, and towards lowercase 'a'.
     #
     #    >> Generators.alphanumeric_string.sample(5, size: 10, rng: Random.new(42))
     #    => ["ZCoQ", "8uM", "wkkx0JNx", "v0bxRDLb", "Gl5v8RyWA6"]
-    def alphanumeric_string
-      array(alphanumeric_char).map(&:join)
+    def alphanumeric_string(**kwargs)
+      array(alphanumeric_char, **kwargs).map(&:join)
     end
 
     @printable_ascii_chars = (' '..'~').to_a.freeze
 
     ##
@@ -300,12 +326,12 @@
     #
     # Shrinks towards fewer characters, and towards ' '.
     #
     #    >> Generators.printable_ascii_string.sample(5, size: 10, rng: Random.new(42))
     #    => ["S|.g", "rvjjw7\"5T!", "=", "!_[4@", "Y"]
-    def printable_ascii_string
-      array(printable_ascii_char).map(&:join)
+    def printable_ascii_string(**kwargs)
+      array(printable_ascii_char, **kwargs).map(&:join)
     end
 
     @ascii_chars = [
       @printable_ascii_chars,
       [
@@ -339,12 +365,12 @@
     #
     # Shrinks towards fewer characters, and towards '\n'.
     #
     #    >> Generators.ascii_string.sample(5, size: 10, rng: Random.new(42))
     #    => ["S|.g", "drvjjw\b\a7\"", "!w=E!_[4@k", "x", "zZI{[o"]
-    def ascii_string
-      array(ascii_char).map(&:join)
+    def ascii_string(**kwargs)
+      array(ascii_char, **kwargs).map(&:join)
     end
 
     @printable_chars = [
       @ascii_chars,
       "\u{A0}".."\u{D7FF}",
@@ -370,12 +396,12 @@
     #
     # Shrinks towards shorter strings, and towards characters with lower codepoints, e.g. ASCII
     #
     #    >> Generators.printable_string.sample(5, size: 10, rng: Random.new(42))
     #    => ["", "Ȍ", "𐁂", "Ȕ", ""]
-    def printable_string
-      array(printable_char).map(&:join)
+    def printable_string(**kwargs)
+      array(printable_char, **kwargs).map(&:join)
     end
 
     ##
     # Generates a single unicode character
     # (both printable and non-printable).
@@ -396,11 +422,11 @@
     #
     # Shrinks towards characters with lower codepoints, e.g. ASCII
     #
     #    >> Generators.string.sample(5, size: 10, rng: Random.new(42))
     #    => ["\u{A3DB3}𠍜\u{3F46A}\u{1AEBC}", "􍙦𡡹󴇒\u{DED74}𪱣\u{43E97}ꂂ\u{50695}􏴴\u{C0301}", "\u{4FD9D}", "\u{C14BF}\u{193BB}𭇋󱣼\u{76B58}", "𦐺\u{9FDDB}\u{80ABB}\u{9E3CF}𐂽\u{14AAE}"]
-    def string
-      array(char).map(&:join)
+    def string(**kwargs)
+      array(char, **kwargs).map(&:join)
     end
 
     ##
     # Generates either `true` or `false`
     #