Rework the tests to check actual values

Rather that testing that the function return the same or different
values, test the actual returned value so that we are sure the behavior
does not change unexpectedly.

Author: smortex

spec/functions/fqdn_rand_string_spec.rb

@@ -25,49 +25,31 @@
   it { is_expected.to run.with_params(100, 'ab').and_return(%r{\A[ab]{100}\z}) }
   it { is_expected.to run.with_params(100, 'ãβ').and_return(%r{\A[ãβ]{100}\z}) }
 
-  it "provides the same 'random' value on subsequent calls for the same host" do
-    expect(fqdn_rand_string(10)).to eql(fqdn_rand_string(10))
-  end
-
-  it 'considers the same host and same extra arguments to have the same random sequence' do
-    first_random = fqdn_rand_string(10, extra_identifier: [1, 'same', 'host'])
-    second_random = fqdn_rand_string(10, extra_identifier: [1, 'same', 'host'])
-
-    expect(first_random).to eql(second_random)
-  end
-
-  it 'allows extra arguments to control the random value on a single host' do
-    first_random = fqdn_rand_string(10, extra_identifier: [1, 'different', 'host'])
-    second_different_random = fqdn_rand_string(10, extra_identifier: [2, 'different', 'host'])
-
-    expect(first_random).not_to eql(second_different_random)
-  end
-
-  it 'returns different strings for different hosts' do
-    val1 = fqdn_rand_string(10, host: 'first.host.com')
-    val2 = fqdn_rand_string(10, host: 'second.host.com')
-
-    expect(val1).not_to eql(val2)
-  end
+  context 'produce predictible and reproducible results' do
+    before(:each) do
+      if Gem::Version.new(Puppet::PUPPETVERSION) < Gem::Version.new('7.23.0')
+        allow(scope).to receive(:lookupvar).with('::fqdn', {}).and_return(fqdn)
+      else
+        allow(scope).to receive(:lookupvar).with('facts', {}).and_return({ 'networking' => { 'fqdn' => fqdn } })
+      end
+    end
 
-  def fqdn_rand_string(max, args = {})
-    host = args[:host] || '127.0.0.1'
-    charset = args[:charset]
-    extra = args[:extra_identifier] || []
+    context 'on a node named example.com' do
+      let(:fqdn) { 'example.com' }
 
-    # workaround not being able to use let(:facts) because some tests need
-    # multiple different hostnames in one context
-    if Gem::Version.new(Puppet::PUPPETVERSION) < Gem::Version.new('7.23.0')
-      allow(scope).to receive(:lookupvar).with('::fqdn', {}).and_return(host)
-    else
-      allow(scope).to receive(:lookupvar).with('facts', {}).and_return({ 'networking' => { 'fqdn' => host } })
+      it { is_expected.to run.with_params(5).and_return('Pw5NP') }
+      it { is_expected.to run.with_params(10, 'abcd').and_return('cdadaaacaa') }
+      it { is_expected.to run.with_params(20, '', 'custom seed').and_return('3QKQHP4wmEObY3a6hkeg') }
+      it { is_expected.to run.with_params(20, '', 'custom seed', 1, 'extra').and_return('OA19SVDoc3QPY5NlSQ28') }
     end
 
-    function_args = [max]
-    if args.key?(:charset) || !extra.empty?
-      function_args << charset
+    context 'on a node named desktop-fln40kq.lan' do
+      let(:fqdn) { 'desktop-fln40kq.lan' }
+
+      it { is_expected.to run.with_params(5).and_return('bgQsB') }
+      it { is_expected.to run.with_params(10, 'abcd').and_return('bcdbcdacad') }
+      it { is_expected.to run.with_params(20, '', 'custom seed').and_return('KaZsFlWkUo5SeA3gBEf0') }
+      it { is_expected.to run.with_params(20, '', 'custom seed', 1, 'extra').and_return('dcAzn1e8AA7hhoLpxAD6') }
     end
-    function_args += extra
-    scope.function_fqdn_rand_string(function_args)
   end
 end