[Go] return errors that happen while unmarshalling objects

[ctreatma]

This updates the Go client templates so that the UnmarshalJSON function for a model always returns errors that occur during unmarshalling.

Given the following spec (pseudocode, not necessarily a fully-valid spec):

components:
  schemas:
    ItemType:
      type: string
      enum:
        - foo
        - bar
        - baz
    Item:
      type: object
      properties:
        type:
          $ref: '#/ItemType'

and the following JSON for an Item:

{
  "type": "invalid"
}

The generated Go model should throw an error in UnmarshalJSON because the value of the type field does not match the spec.

cc/ Go committe: @antihax @grokify @kemokemo @jirikuncar @ph4r5h4d @lwj5

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• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
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  ./mvnw clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

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  ./bin/utils/ensure-up-to-date
  

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[ctreatma]

CI says samples are not up-to-date, but the changes it's finding are unrelated to my PR; I'm not sure how to address this.

Example diff reported by CI job:

-// HasType returns a boolean if a field has been set.
-func (o *PropertyNameMapping) HasType() bool {
-	if o != nil && !IsNil(o.Type) {
+// HasTypeWithUnderscore returns a boolean if a field has been set.
+func (o *PropertyNameMapping) HasTypeWithUnderscore() bool {
+	if o != nil && !IsNil(o.TypeWithUnderscore) {
 		return true
 	}
 
 	return false
 }

[wing328]

CircleCI reported the following errors:

        go-petstore/model_property_name_mapping.go:91:31: other declaration of GetTypeOk
go-petstore/model_property_name_mapping.go:163:31: PropertyNameMapping.HasType redeclared in this block
        go-petstore/model_property_name_mapping.go:99:31: other declaration of HasType
go-petstore/model_property_name_mapping.go:172:31: PropertyNameMapping.SetType redeclared in this block
        go-petstore/model_property_name_mapping.go:108:31: other declaration of SetType
go-petstore/model_property_name_mapping.go:172:31: too many errors
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (go-test) on project GoOAS3Petstore: Command execution failed.: Process exited with an error: 2 (Exit value: 2) -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.

ref: https://app.circleci.com/pipelines/github/OpenAPITools/openapi-generator/25568/workflows/098b15c0-fac5-43d1-84d1-6d769962cf3a/jobs/77623

Can you please take a look when you've time?

[wing328]

for the updated samples, can you please merge the latest master into your branch and regenerate the samples again?

[ctreatma]

This change matches a change that was made in November 2022 in samples/client/petstore/go/store_api_test.go.

I wouldn't expect my template change to impact this test...was this broken before or did my template change break it?

[wing328]

It was working before. To run the tests locally, please refer to https://github.com/OpenAPITools/openapi-generator/wiki/Integration-Tests#how-to-add-integration-tests-for-new-petstore-samples

[ctreatma]

I did run the tests locally to fix the issue but hadn't run them against master locally to confirm the initial state. It took me a minute to connect the new test failure to my change because I didn't change anything about time parsing. The test was passing before because errors weren't being returned at all, so there was no time parse error to ignore; with my change to return errors, the test started failing because the regex it was using to identify time parse errors was wrong. (Go playground example for posterity)

[wing328]

@ctreatma thanks for the details. Can you please PM me vis Slack when you've time?

https://join.slack.com/t/openapi-generator/shared_invite/zt-12jxxd7p2-XUeQM~4pzsU9x~eGLQqX2g