Simplify script validation error message

Simplifies script validation error messages and adds more specs to cover
the changes.

ee/spec/lib/gitlab/web_ide/config/entry/global_spec.rb

@@ -109,7 +109,7 @@ describe Gitlab::WebIde::Config::Entry::Global do
       describe '#errors' do
         it 'reports errors about missing script' do
           expect(global.errors)
-            .to include "terminal:before_script config should be an array of strings"
+            .to include "terminal:before_script config should be an array of strings and arrays of strings"
         end
       end
     end

lib/gitlab/ci/config/entry/commands.rb

@@ -14,7 +14,7 @@ module Gitlab
             validate do
               unless config.is_a?(String) ||
                   (config.is_a?(Array) && config.all? { |element| element.is_a?(String) || validate_array_of_strings?(element) })
-                errors.add(:config, 'should be an array of strings and arrays of strings or string')
+                errors.add(:config, 'should be a string or an array of strings and arrays of strings')
               end
             end
 

lib/gitlab/ci/config/entry/script.rb

@@ -13,7 +13,7 @@ module Gitlab
           validations do
             validate do
               unless config.is_a?(Array) && config.all? { |element| element.is_a?(String) || validate_array_of_strings?(element) }
-                errors.add(:config, 'should be an array of strings and arrays of strings or string')
+                errors.add(:config, 'should be an array of strings and arrays of strings')
               end
             end
 

spec/lib/gitlab/ci/config/entry/commands_spec.rb

@@ -87,7 +87,7 @@ describe Gitlab::Ci::Config::Entry::Commands do
     describe '#errors' do
       it 'saves errors' do
         expect(entry.errors)
-          .to include 'commands config should be an array of strings and arrays of strings or string'
+          .to include 'commands config should be a string or an array of strings and arrays of strings'
       end
     end
   end
@@ -98,7 +98,7 @@ describe Gitlab::Ci::Config::Entry::Commands do
     describe '#errors' do
       it 'saves errors' do
         expect(entry.errors)
-          .to include 'commands config should be an array of strings and arrays of strings or string'
+          .to include 'commands config should be a string or an array of strings and arrays of strings'
       end
     end
 

spec/lib/gitlab/ci/config/entry/root_spec.rb

@@ -293,7 +293,7 @@ describe Gitlab::Ci::Config::Entry::Root do
       describe '#errors' do
         it 'reports errors from child nodes' do
           expect(root.errors)
-            .to include 'before_script config should be an array of strings'
+            .to include 'before_script config should be an array of strings and arrays of strings'
         end
       end
     end

spec/lib/gitlab/ci/config/entry/script_spec.rb

@@ -78,7 +78,7 @@ describe Gitlab::Ci::Config::Entry::Script do
       describe '#errors' do
         it 'saves errors' do
           expect(entry.errors)
-            .to include 'script config should be an array of strings and arrays of strings or string'
+            .to include 'script config should be an array of strings and arrays of strings'
         end
       end
 
@@ -95,7 +95,7 @@ describe Gitlab::Ci::Config::Entry::Script do
       describe '#errors' do
         it 'saves errors' do
           expect(entry.errors)
-            .to include 'script config should be an array of strings and arrays of strings or string'
+            .to include 'script config should be an array of strings and arrays of strings'
         end
       end
 

spec/lib/gitlab/ci/pipeline/chain/validate/config_spec.rb

@@ -94,7 +94,7 @@ describe Gitlab::Ci::Pipeline::Chain::Validate::Config do
 
     it 'appends configuration validation errors to pipeline errors' do
       expect(pipeline.errors.to_a)
-        .to include "jobs:rspec:before_script config should be an array of strings"
+        .to include "jobs:rspec:before_script config should be an array of strings and arrays of strings"
     end
 
     it 'breaks the chain' do

spec/lib/gitlab/ci/yaml_processor_spec.rb

@@ -1587,28 +1587,42 @@ module Gitlab
           config = YAML.dump({ before_script: "bundle update", rspec: { script: "test" } })
           expect do
             Gitlab::Ci::YamlProcessor.new(config)
-          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "before_script config should be an array of strings")
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "before_script config should be an array of strings and arrays of strings")
         end
 
         it "returns errors if job before_script parameter is not an array of strings" do
           config = YAML.dump({ rspec: { script: "test", before_script: [10, "test"] } })
           expect do
             Gitlab::Ci::YamlProcessor.new(config)
-          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:before_script config should be an array of strings")
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:before_script config should be an array of strings and arrays of strings")
+        end
+
+        it "returns errors if job before_script parameter is multi-level nested array of strings" do
+          config = YAML.dump({ rspec: { script: "test", before_script: [["ls", ["pwd"]], "test"] } })
+          expect do
+            Gitlab::Ci::YamlProcessor.new(config)
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:before_script config should be an array of strings and arrays of strings")
         end
 
         it "returns errors if after_script parameter is invalid" do
           config = YAML.dump({ after_script: "bundle update", rspec: { script: "test" } })
           expect do
             Gitlab::Ci::YamlProcessor.new(config)
-          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "after_script config should be an array of strings")
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "after_script config should be an array of strings and arrays of strings")
         end
 
         it "returns errors if job after_script parameter is not an array of strings" do
           config = YAML.dump({ rspec: { script: "test", after_script: [10, "test"] } })
           expect do
             Gitlab::Ci::YamlProcessor.new(config)
-          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:after_script config should be an array of strings")
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:after_script config should be an array of strings and arrays of strings")
+        end
+
+        it "returns errors if job after_script parameter is multi-level nested array of strings" do
+          config = YAML.dump({ rspec: { script: "test", after_script: [["ls", ["pwd"]], "test"] } })
+          expect do
+            Gitlab::Ci::YamlProcessor.new(config)
+          end.to raise_error(Gitlab::Ci::YamlProcessor::ValidationError, "jobs:rspec:after_script config should be an array of strings and arrays of strings")
         end
 
         it "returns errors if image parameter is invalid" do