Better debugging output for bad api.yaml values (GoogleCloudPlatform#…

…1731)

Merged PR GoogleCloudPlatform#1731.

api/product.rb

@@ -39,6 +39,13 @@ def to_s
       JSON.pretty_generate(self)
     end
 
+    # Prints a dot notation path to where the field is nested within the parent
+    # object when called on a property. eg: parent.meta.label.foo
+    # Redefined on Product to terminate the calls up the parent chain.
+    def lineage
+      name
+    end
+
     def to_json(opts = nil)
       json_out = {}
 

api/resource.rb

@@ -172,6 +172,13 @@ def to_s
       JSON.pretty_generate(self)
     end
 
+    # Prints a dot notation path to where the field is nested within the parent
+    # object when called on a property. eg: parent.meta.label.foo
+    # Redefined on Resource to terminate the calls up the parent chain.
+    def lineage
+      name
+    end
+
     def to_json(opts = nil)
       # ignore fields that will contain references to parent resources
       ignored_fields = %i[@__product @__parent @__resource @api_name @collection_url_response]

api/type.rb

@@ -84,6 +84,16 @@ def to_s
       JSON.pretty_generate(self)
     end
 
+    # Prints a dot notation path to where the field is nested within the parent
+    # object. eg: parent.meta.label.foo
+    # The only intended purpose is to allow better error messages. Some objects
+    # and at some points in the build this doesn't ouput a valid output.
+    def lineage
+      return name if __parent.nil?
+
+      __parent.lineage + '.' + name
+    end
+
     def to_json(opts = nil)
       # ignore fields that will contain references to parent resources and
       # those which will be added later
@@ -454,6 +464,8 @@ def all_properties
       end
 
       def properties
+        raise "Field '#{lineage}' properties are nil!" if @properties.nil?
+
         @properties.reject(&:exclude)
       end
 

google/yaml_validator.rb

@@ -59,16 +59,17 @@ def check(variable, **opts)
         value = instance_variable_get("@#{variable}")
       end
 
-      # Check if value is required.
-      raise "Missing '#{variable}'" if value.nil? && opts[:required]
+      # Check if value is required. Print nested path if available.
+      lineage_path = respond_to?('lineage') ? lineage : ''
+      raise "#{lineage_path} > Missing '#{variable}'" if value.nil? && opts[:required]
       return if value.nil?
 
       # Check type
       check_property_value(variable, value, opts[:type]) if opts[:type]
 
       # Check item_type
       if value.is_a?(Array)
-        raise "#{variable} must have item_type on arrays" unless opts[:item_type]
+        raise "#{lineage_path} > #{variable} must have item_type on arrays" unless opts[:item_type]
 
         value.each_with_index do |o, index|
           check_property_value("#{variable}[#{index}]", o, opts[:item_type])

overrides/validator.rb

@@ -69,12 +69,20 @@ def verify_properties(properties, overrides, res_name = '')
 
     # Returns a property (or throws an error if it does not exist)
     def find_property(properties, path, res_name = '')
+      # Add context for debugging property name typos
+      available = []
+      prefix = ''
+
       prop = nil
       path.each do |part|
+        available = properties.map { |p| prefix + p.name } unless properties.empty?
+        prefix = prefix + part + '.'
+
         prop = properties.select { |o| o.name == part }.first
         properties = prop&.nested_properties || []
       end
-      raise "#{path.join('.')} does not exist on #{res_name}" unless prop
+      raise "#{path.join('.')} does not exist on #{res_name}.\n Possible values #{available}" \
+        unless prop
 
       prop
     end

spec/override_validator_spec.rb

@@ -34,7 +34,7 @@ def self.attributes
       it {
         runner = Overrides::Validator.new(api, overrides)
         expect { runner.run }.to raise_error(RuntimeError,
-                                             '@blahbad does not exist on AnotherResource')
+                                             /@blahbad does not exist on AnotherResource/)
       }
     end
     describe 'should be able identify a bad property' do
@@ -54,7 +54,7 @@ def self.attributes
       it {
         runner = Overrides::Validator.new(api, overrides)
         expect { runner.run }.to raise_error(RuntimeError,
-                                             'blahbad does not exist on AnotherResource')
+                                             /blahbad does not exist on AnotherResource/)
       }
     end