Verbose test syntax

README.md

@@ -73,6 +73,36 @@ describe "plus" do
   end
 end
 
+# Verbose Syntax
+# For complex inputs or if you just want to be super explicit
+describe "Verbose syntax" do
+  where do
+    {
+      "positive integers" => {
+        a: 1,
+        b: 2,
+        answer: 3,
+      },
+      "negative_integers" => {
+        a: -1,
+        b: -2,
+        answer: -3,
+      },
+      "mixed_integers" => {
+        a: 3,
+        b: -3,
+        answer: 0,
+      },
+    }
+  end
+
+  with_them do
+    it "should do additions" do
+      expect(a + b).to eq answer
+    end
+  end
+end
+
 # It's also possible to override each combination name using magic variable :case_name
 # Output:
 # Custom test case name

lib/rspec/parameterized.rb

@@ -54,6 +54,8 @@ def where(*args, &b)
           set_parameters(arg_names) {
             arg_values
           }
+        elsif args.size == 0
+          set_verbose_parameters(&b)
         else
           set_parameters(args, &b)
         end
@@ -143,6 +145,23 @@ def params_inspect(obj)
           return obj.inspect
         end
       end
+
+      def set_verbose_parameters(&block)
+        arguments_hash = yield
+        arg_names = arguments_hash.values.reduce(Set.new) { |memo, pairs| memo | pairs.keys }.to_a
+        arg_values = []
+        arguments_hash.each do |name, values_hash|
+          row = [name]
+          arg_names.each do |argument_name|
+              row << values_hash[argument_name]
+          end
+          arg_values << row
+        end
+        arg_names.unshift(:case_name)
+        set_parameters(arg_names) {
+          arg_values
+        }
+      end
     end
   end
 

spec/parametarized_spec.rb

@@ -66,6 +66,71 @@
     end
   end
 
+  describe "Verbose syntax" do
+    where do
+      {
+        "positive integers" => {
+          a: 1,
+          b: 2,
+          answer: 3,
+        },
+        "negative_integers" => {
+          a: -1,
+          b: -2,
+          answer: -3,
+        },
+        "mixed_integers" => {
+          a: 3,
+          b: -3,
+          answer: 0,
+        },
+      }
+    end
+
+    with_them do
+      it "should do additions" do
+        expect(a + b).to eq answer
+      end
+
+      it "should have custom name" do |example|
+        expect(example.metadata[:example_group][:description]).to eq case_name
+      end
+    end
+
+    context "lambda parameter" do
+      where do
+        {
+          "integers" => {
+            a: 1,
+            b: 2,
+            answer: -> {expect(subject).to eq 3},
+          },
+          "strings" => {
+            a: "hello ",
+            b: "world",
+            answer: -> {expect(subject).to include "lo wo"},
+          },
+          "arrays" => {
+            a: [1, 2, 3],
+            b: [4, 5, 6],
+            answer: -> {expect(subject.size).to eq 6}
+          }
+        }
+      end
+
+      with_them do
+        subject {a + b}
+        it "should do additions" do
+          self.instance_exec(&answer)
+        end
+
+        it "should have custom name" do |example|
+          expect(example.metadata[:example_group][:description]).to eq(case_name)
+        end
+      end
+    end
+  end
+
   describe "Custom test case name" do
     context "when regular arguments" do
       where(:case_name, :a, :b, :answer) do