Rewrite loadjson to use the modern function API

This also resolves a bug where JSON.parse returned a StringIO. To
properly catch this, the tests are rewritten to avoid mocking where
possible. Exceptions are with external URLs and where a failure is
expected.

lib/puppet/functions/loadjson.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+# @summary
+#   Load a JSON file containing an array, string, or hash, and return the data
+#   in the corresponding native data type.
+#
+# @example Example Usage:
+#   $myhash = loadjson('/etc/puppet/data/myhash.json')
+#   $myhash = loadjson('https://example.local/my_hash.json')
+#   $myhash = loadjson('https://username:password@example.local/my_hash.json')
+#   $myhash = loadjson('no-file.json', {'default' => 'value'})
+Puppet::Functions.create_function(:loadjson) do
+  # @param path
+  #   A file path or a URL.
+  # @param default
+  #   The default value to be returned if the file was not found or could not
+  #   be parsed.
+  #
+  # @return
+  #   The data stored in the JSON file, the type depending on the type of data
+  #   that was stored.
+  dispatch :loadjson do
+    param 'String[1]', :path
+    optional_param 'Data', :default
+    return_type 'Data'
+  end
+
+  def loadjson(path, default = nil)
+    if path.start_with?('http://', 'https://')
+      require 'open-uri'
+      begin
+        content = URI.open(path) { |f| load_json_source(f) }
+      rescue OpenURI::HTTPError => e
+        Puppet.warn("Can't load '#{url}' HTTP Error Code: '#{e.io.status[0]}'")
+        return default
+      end
+    elsif File.exist?(path)
+      content = File.open(path) { |f| load_json_source(f) }
+    else
+      Puppet.warn("Can't load '#{path}' File does not exist!")
+      return default
+    end
+
+    content || default
+  rescue StandardError => e
+    raise e unless default
+
+    default
+  end
+
+  def load_json_source(source)
+    if Puppet::Util::Package.versioncmp(Puppet.version, '8.0.0').negative?
+      PSON.load(source)
+    else
+      JSON.load(source)
+    end
+  end
+end

spec/functions/loadjson_spec.rb

@@ -1,178 +1,99 @@
 # frozen_string_literal: true
 
 require 'spec_helper'
+require 'open-uri'
 
 describe 'loadjson' do
   it { is_expected.not_to be_nil }
-  it { is_expected.to run.with_params.and_raise_error(ArgumentError, %r{wrong number of arguments}i) }
+  it { is_expected.to run.with_params.and_raise_error(ArgumentError, "'loadjson' expects between 1 and 2 arguments, got none") }
 
   describe 'when calling with valid arguments' do
-    before :each do
-      # In Puppet 7, there are two prior calls to File.read prior to the responses we want to mock
-      allow(File).to receive(:read).with(anything, anything).and_call_original
-      allow(File).to receive(:read).with(%r{/(stdlib|test)/metadata.json}, encoding: 'utf-8').and_return('{"name": "puppetlabs-stdlib"}')
-      allow(File).to receive(:read).with(%r{/(stdlib|test)/metadata.json}).and_return('{"name": "puppetlabs-stdlib"}')
-      # Additional modules used by litmus which are identified while running these dues to being in fixtures
-      allow(File).to receive(:read).with(%r{/(provision|puppet_agent|facts)/metadata.json}, encoding: 'utf-8')
-    end
-
     context 'when a non-existing file is specified' do
       let(:filename) do
-        if Puppet::Util::Platform.windows?
-          'C:/tmp/doesnotexist'
-        else
-          '/tmp/doesnotexist'
-        end
+        file = Tempfile.create
+        file.close
+        File.unlink(file.path)
+        file.path
       end
 
       before(:each) do
-        allow(File).to receive(:exist?).and_call_original
-        allow(File).to receive(:exist?).with(filename).and_return(false).once
         if Puppet::PUPPETVERSION[0].to_i < 8
           allow(PSON).to receive(:load).never # rubocop:disable RSpec/ReceiveNever  Switching to not_to receive breaks testing in this case
         else
           allow(JSON).to receive(:parse).never # rubocop:disable RSpec/ReceiveNever
         end
       end
 
-      it { is_expected.to run.with_params(filename, 'default' => 'value').and_return('default' => 'value') }
-      it { is_expected.to run.with_params(filename, 'đẽƒằưļŧ' => '٧ẵłựέ').and_return('đẽƒằưļŧ' => '٧ẵłựέ') }
-      it { is_expected.to run.with_params(filename, 'デフォルト' => '値').and_return('デフォルト' => '値') }
+      it { is_expected.to run.with_params(filename, {'default' => 'value'}).and_return({'default' => 'value'}) }
+      it { is_expected.to run.with_params(filename, {'đẽƒằưļŧ' => '٧ẵłựέ'}).and_return({'đẽƒằưļŧ' => '٧ẵłựέ'}) }
+      it { is_expected.to run.with_params(filename, {'デフォルト' => '値'}).and_return({'デフォルト' => '値'}) }
     end
 
     context 'when an existing file is specified' do
-      let(:filename) do
-        if Puppet::Util::Platform.windows?
-          'C:/tmp/doesexist'
-        else
-          '/tmp/doesexist'
-        end
-      end
       let(:data) { { 'key' => 'value', 'ķęŷ' => 'νậŀųề', 'キー' => '値' } }
       let(:json) { '{"key":"value", {"ķęŷ":"νậŀųề" }, {"キー":"値" }' }
 
-      before(:each) do
-        allow(File).to receive(:exist?).and_call_original
-        allow(File).to receive(:exist?).with(filename).and_return(true).once
-        allow(File).to receive(:read).with(filename).and_return(json).once
-        allow(File).to receive(:read).with(filename).and_return(json).once
-        if Puppet::PUPPETVERSION[0].to_i < 8
-          allow(PSON).to receive(:load).with(json).and_return(data).once
-        else
-          allow(JSON).to receive(:parse).with(json).and_return(data).once
+      it do
+        Tempfile.new do |file|
+          file.write(json)
+          file.flush
+
+          is_expected.to run.with_params(file.path).and_return(data)
         end
       end
-
-      it { is_expected.to run.with_params(filename).and_return(data) }
     end
 
     context 'when the file could not be parsed' do
-      let(:filename) do
-        if Puppet::Util::Platform.windows?
-          'C:/tmp/doesexist'
-        else
-          '/tmp/doesexist'
-        end
-      end
       let(:json) { '{"key":"value"}' }
 
-      before(:each) do
-        allow(File).to receive(:exist?).and_call_original
-        allow(File).to receive(:exist?).with(filename).and_return(true).once
-        allow(File).to receive(:read).with(filename).and_return(json).once
-        if Puppet::PUPPETVERSION[0].to_i < 8
-          allow(PSON).to receive(:load).with(json).once.and_raise StandardError, 'Something terrible have happened!'
-        else
-          allow(JSON).to receive(:parse).with(json).once.and_raise StandardError, 'Something terrible have happened!'
-        end
-      end
-
-      it { is_expected.to run.with_params(filename, 'default' => 'value').and_return('default' => 'value') }
-    end
-
-    context 'when an existing URL is specified' do
-      let(:filename) do
-        'https://example.local/myhash.json'
-      end
-      let(:data) { { 'key' => 'value', 'ķęŷ' => 'νậŀųề', 'キー' => '値' } }
-      let(:json) { '{"key":"value", {"ķęŷ":"νậŀųề" }, {"キー":"値" }' }
+      it do
+        Tempfile.new do |file|
+          file.write(json)
+          file.flush
 
-      it {
-        expect(OpenURI).to receive(:open_uri).with(filename, {}).and_return(json)
-        if Puppet::PUPPETVERSION[0].to_i < 8
-          expect(PSON).to receive(:load).with(json).and_return(data).once
-        else
-          expect(JSON).to receive(:parse).with(json).and_return(data).once
+          is_expected.to run.with_params(filename, {'default' => 'value'}).and_return({'default' => 'value'})
         end
-        expect(subject).to run.with_params(filename).and_return(data)
-      }
-    end
-
-    context 'when an existing URL (with username and password) is specified' do
-      let(:filename) do
-        'https://user1:pass1@example.local/myhash.json'
       end
-      let(:url_no_auth) { 'https://example.local/myhash.json' }
-      let(:basic_auth) { { http_basic_authentication: ['user1', 'pass1'] } }
-      let(:data) { { 'key' => 'value', 'ķęŷ' => 'νậŀųề', 'キー' => '値' } }
-      let(:json) { '{"key":"value", {"ķęŷ":"νậŀųề" }, {"キー":"値" }' }
-
-      it {
-        expect(OpenURI).to receive(:open_uri).with(url_no_auth, basic_auth).and_return(json)
-        if Puppet::PUPPETVERSION[0].to_i < 8
-          expect(PSON).to receive(:load).with(json).and_return(data).once
-        else
-          expect(JSON).to receive(:parse).with(json).and_return(data).once
-        end
-        expect(subject).to run.with_params(filename).and_return(data)
-      }
     end
 
-    context 'when an existing URL (with username) is specified' do
+    context 'when an existing URL is specified' do
       let(:filename) do
-        'https://user1@example.local/myhash.json'
+        'https://example.com/myhash.json'
       end
-      let(:url_no_auth) { 'https://example.local/myhash.json' }
-      let(:basic_auth) { { http_basic_authentication: ['user1', ''] } }
       let(:data) { { 'key' => 'value', 'ķęŷ' => 'νậŀųề', 'キー' => '値' } }
-      let(:json) { '{"key":"value", {"ķęŷ":"νậŀųề" }, {"キー":"値" }' }
+      let(:json) { '{"key":"value", "ķęŷ":"νậŀųề", "キー":"値" }' }
 
       it {
-        expect(OpenURI).to receive(:open_uri).with(url_no_auth, basic_auth).and_return(json)
-        if Puppet::PUPPETVERSION[0].to_i < 8
-          expect(PSON).to receive(:load).with(json).and_return(data).once
-        else
-          expect(JSON).to receive(:parse).with(json).and_return(data).once
-        end
+        expect(URI).to receive(:open).with(filename).and_yield(json)
         expect(subject).to run.with_params(filename).and_return(data)
       }
     end
 
     context 'when the URL output could not be parsed, with default specified' do
       let(:filename) do
-        'https://example.local/myhash.json'
+        'https://example.com/myhash.json'
       end
       let(:json) { ',;{"key":"value"}' }
 
       it {
-        expect(OpenURI).to receive(:open_uri).with(filename, {}).and_return(json)
+        expect(URI).to receive(:open).with(filename).and_yield(json)
         if Puppet::PUPPETVERSION[0].to_i < 8
           expect(PSON).to receive(:load).with(json).once.and_raise StandardError, 'Something terrible have happened!'
         else
-          expect(JSON).to receive(:parse).with(json).once.and_raise StandardError, 'Something terrible have happened!'
+          expect(JSON).to receive(:load).with(json).once.and_raise StandardError, 'Something terrible have happened!'
         end
-        expect(subject).to run.with_params(filename, 'default' => 'value').and_return('default' => 'value')
+        expect(subject).to run.with_params(filename, {'default' => 'value'}).and_return({'default' => 'value'})
       }
     end
 
     context 'when the URL does not exist, with default specified' do
       let(:filename) do
-        'https://example.local/myhash.json'
+        'https://example.com/myhash.json'
       end
 
       it {
-        expect(OpenURI).to receive(:open_uri).with(filename, {}).and_raise OpenURI::HTTPError, '404 File not Found'
-        expect(subject).to run.with_params(filename, 'default' => 'value').and_return('default' => 'value')
+        expect(URI).to receive(:open).with(filename).and_raise OpenURI::HTTPError, '404 File not Found'
+        expect(subject).to run.with_params(filename, {'default' => 'value'}).and_return({'default' => 'value'})
       }
     end
   end