require "spec_helper" require "hamster/vector" describe Hamster::Vector do let(:vector) { Hamster.vector(*values) } describe "#exist?" do let(:exist?) { vector.exist?(&block) } context "when created with no values" do let(:values) { [] } context "with a block" do let(:block) { ->(item) { item + 1 } } it "returns false" do expect(exist?).to be(false) end end context "with a block" do let(:block) { nil } it "returns false" do expect(exist?).to be(false) end end end context "when created with values" do let(:values) { ["A", "B", 3, nil] } context "with a block that returns true" do let(:block) { ->(item) { item == 3 } } it "returns true" do expect(exist?).to be(true) end end context "with a block that doesn't return true" do let(:block) { ->(item) { item == "D" } } it "returns false" do expect(exist?).to be(false) end end context "without a block" do let(:block) { nil } context "with some values that are truthy" do let(:values) { [nil, false, "B"] } it "returns true" do expect(exist?).to be(true) end end context "with all values that are falsey" do let(:values) { [nil, false] } it "returns false" do expect(exist?).to be(false) end end end end end end