Fix readonly handling

The database `readonly` property expects a boolean, but the olc
provider doesn't take care to parse the existing value into a boolean,
thus leading to issues.

Simply applies the same logic applied to `olcMirrorMode` for
`olcReadOnly`.

lib/puppet/provider/openldap_database/olc.rb

@@ -50,7 +50,7 @@ def self.instances
         when %r{^olcRelay: }
           relay = line.split[1]
         when %r{^olcReadOnly: }i
-          readonly = line.split[1]
+          readonly = line.split[1] == 'TRUE' ? :true : :false
         when %r{^olcSizeLimit: }i
           sizelimit = line.split[1]
         when %r{^olcDbMaxSize: }i

lib/puppet/type/openldap_database.rb

@@ -167,6 +167,8 @@ def should_to_s(_newvalue)
 
   newproperty(:readonly) do
     desc 'Puts the database into read-only mode.'
+    newvalues(:true, :false)
+    defaultto(:false)
   end
 
   newproperty(:sizelimit) do

spec/unit/puppet/provider/openldap_database/olc_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Puppet::Type.type(:openldap_database).provider(:olc) do
+  let(:params) do
+    {
+      suffix: 'dc=example,dc=com',
+      backend: 'mdb',
+      readonly: false,
+      # provider: described_class.name,
+    }
+  end
+
+  let(:resource) do
+    Puppet::Type.type(:openldap_database).new(params)
+  end
+  let(:provider) do
+    resource.provider
+  end
+
+  before do
+    allow(described_class).to receive(:slapcat).with('(|(olcDatabase=monitor)(olcDatabase={0}config)(&(objectClass=olcDatabaseConfig)(|(objectClass=olcBdbConfig)(objectClass=olcHdbConfig)(objectClass=olcMdbConfig)(objectClass=olcMonitorConfig)(objectClass=olcRelayConfig)(objectClass=olcLDAPConfig))))').and_return(<<~SLAPCAT)
+      dn: olcDatabase={1}mdb,cn=config
+      olcDatabase: {1}mdb
+      olcReadOnly: FALSE
+    SLAPCAT
+    allow(provider).to receive(:slapcat)
+    allow(provider).to receive(:ldapmodify)
+    allow(provider).to receive(:ldapadd)
+    # allow(described_class).to receive(:slapcat)
+    # allow(described_class).to receive(:ldapmodify)
+    # allow(described_class).to receive(:ldapadd)
+  end
+
+  describe 'when creating' do
+    context 'with readonly set to false' do
+      it 'parses olcReadOnly as false' do
+        provider.create
+        expect(described_class.instances.first.readonly).to eq :false
+        # expect(described_class.instances.first.readonly).to eq(:false)
+      end
+    end
+
+    context 'with readonly set to true' do
+      let(:params) do
+        super().merge({ readonly: true })
+      end
+
+      it 'parses olcReadonly' do
+        expect(described_class.instances.first.readonly).to eq(:true)
+      end
+    end
+  end
+end