Use RegexMatcher to force used =~ operator

src/spectator/matchers/regex_matcher.cr

@@ -0,0 +1,40 @@
+require "./value_matcher"
+
+module Spectator::Matchers
+  # Common matcher that tests whether a value matches another.
+  # The values are compared with the =~ operator.
+  struct RegexMatcher(ExpectedType) < ValueMatcher(ExpectedType)
+    # Short text about the matcher's purpose.
+    # This explains what condition satisfies the matcher.
+    # The description is used when the one-liner syntax is used.
+    def description : String
+      "matches #{expected.label}"
+    end
+
+    # Checks whether the matcher is satisifed with the expression given to it.
+    private def match?(actual : Expression(T)) : Bool forall T
+      !!(actual.value =~ expected.value)
+    end
+
+    # Message displayed when the matcher isn't satisifed.
+    #
+    # This is only called when `#match?` returns false.
+    #
+    # The message should typically only contain the test expression labels.
+    # Actual values should be returned by `#values`.
+    private def failure_message(actual) : String
+      "#{actual.label} does not match #{expected.label}"
+    end
+
+    # Message displayed when the matcher isn't satisifed and is negated.
+    # This is essentially what would satisfy the matcher if it wasn't negated.
+    #
+    # This is only called when `#does_not_match?` returns false.
+    #
+    # The message should typically only contain the test expression labels.
+    # Actual values should be returned by `#values`.
+    private def failure_message_when_negated(actual) : String
+      "#{actual.label} matched #{expected.label}"
+    end
+  end
+end

src/spectator/matchers/truthy_matcher.cr

@@ -99,7 +99,7 @@ module Spectator::Matchers
     # ```
     def =~(value)
       expected = Value.new(value)
-      PatternMatcher.new(expected)
+      RegexMatcher.new(expected)
     end
 
     # Checks whether the matcher is satisifed with the expression given to it.