[go-server] Support min/max/defaults for values

[rledisez]

Enforce, for the go-server, to check the minimum and maximum values specified in the openapi description. Also apply the default if the parameter is not passed.

Fix #14013

@antihax @grokify @kemokemo @jirikuncar @ph4r5h4d @lwj5

[wing328]

can you please resolve the merge conflicts when you've time?

[lwj5]

This seems to return pointers up the stack which may result in heap allocation and slow perf.
As much as possible try to not use ptr of basic types

[lwj5]

Is there a case where a body param is not a schema object?

If multiple body param references the same schema object, this will be duplicated repeatedly.

Could this be moved into the model.mustache?

[lwj5]

instead of using nil all over, and requiring ptr. you can use functional options pattern

[lwj5]

Let me know if you need any help

[rledisez]

Let me know if you need any help

Thx for the review. What's the status on using generics in the go-server generated code? I'd like to use generics for the option pattern to avoid having all the combination of With(Float|Int|String|Bool)(Default|Minimum|Maximum)

I see #15087 was merged in 7.0.x, does it mean generics won't appear in any 6.x releases? If so, what's your recommandation? target 7.0.x for this PR?

[lwj5]

Yup, generics is breaking cause of the go version bump, so will not be in 6. According to wing328, it’s going to be a tentative June release.

If you don’t mind waiting for the new major release or building 7 yourself to use this new feature for the time being. You can create a new branch from 7.0.0, port the changes over, and create a new PR targeting that branch.

[rledisez]

Not sure how to have the imports automatically added. Any help welcome.

[lwj5]

For this, you will have to look at postProcessModels()

may have to override it in modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoServerCodegen.java

Let me know if there's any issues

[rledisez]

New version of the PR, now targeting 7.0.x. I had one trouble with imports (see the comment).

For testing, as I don't see how to test against the public instance, I wrote my own server/client implementation, I uploaded in another branch: rledisez@c83d644

[lwj5]

Just some minor inputs, I'll look at routers in the coming week

[lwj5]

Also help to check the indentations, I found some with 4 spaces. Should be tabs, if not linter will complain

[lwj5]

For router go

you can use something like this

// GetOrderById - Find purchase order by ID
func (c *StoreApiController) GetOrderById(w http.ResponseWriter, r *http.Request) {
	orderIdParam, err := parseNumericParameter[int64](
		chi.URLParam(r, "orderId"),
		WithRequire[int64](parseInt64),
		WithMinimum[int64](1),
		WithMaximum[int64](5),
	)
	if err != nil {
		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
		return
	}

...
}

with something like this

type Number interface {
	constraints.Integer | constraints.Float
}

type ParseString[T Number | string | bool] func(v string) (T, error)

// parseFloat64 parses a string parameter to an float64.
func parseFloat64(param string) (float64, error) {
	return strconv.ParseFloat(param, 64)
}

// parseFloat32 parses a string parameter to an float32.
func parseFloat32(param string) (float32, error) {
	v, err := strconv.ParseFloat(param, 32)
	return float32(v), err
}

// parseInt64 parses a string parameter to an int64.
func parseInt64(param string) (int64, error) {
	return strconv.ParseInt(param, 10, 64)
}

// parseInt32 parses a string parameter to an int32.
func parseInt32(param string) (int32, error) {
	val, err := strconv.ParseInt(param, 10, 32)
	return int32(val), err
}

// parseBool parses a string parameter to an bool.
func parseBool(param string) (bool, error) {
	return strconv.ParseBool(param)
}

type Operation[T Number | string | bool] func(actual string) (T, bool, error)

func WithRequire[T Number | string | bool](parse ParseString[T]) Operation[T] {
	var empty T
	return func(actual string) (T, bool, error) {
		if actual == "" {
			return empty, false, errors.New(errMsgRequiredMissing)
		}

		v, err := parse(actual)
		return v, false, err
	}
}

func WithDefaultOrParse[T Number | string | bool](def T, parse ParseString[T]) Operation[T] {
	return func(actual string) (T, bool, error) {
		if actual == "" {
			return def, true, nil
		}

		v, err := parse(actual)
		return v, false, err
	}
}

func WithParse[T Number | string | bool](parse ParseString[T]) Operation[T] {
	return func(actual string) (T, bool, error) {
		v, err := parse(actual)
		return v, false, err
	}
}

type Constraint[T Number | string | bool] func(actual T) error

func WithMinimum[T Number](expected T) Constraint[T] {
	return func(actual T) error {
		if actual < expected {
			return errors.New(errMsgMinValueConstraint)
		}

		return nil
	}
}

func WithMaximum[T Number](expected T) Constraint[T] {
	return func(actual T) error {
		if actual > expected {
			return errors.New(errMsgMaxValueConstraint)
		}

		return nil
	}
}

// parseNumericParameter parses a numeric parameter to an its respective type.
func parseNumericParameter[T Number](param string, fn Operation[T], check ...Constraint[T]) (T, error) {
	v, ok, err := fn(param)
	if err != nil {
		return 0, err
	}

	if !ok {
		for _, o := range check {
			if err := o(v); err != nil {
				return 0, err
			}
		}
	}

	return v, nil
}

// parseBoolParameter parses a string parameter to a bool
func parseBoolParameter(param string, fn Operation[bool]) (bool, error) {
	v, _, err := fn(param)
	return v, err
}

please do a sanity check if you can

[rledisez]

I think I did all suggested changes. For the java change, the IDE (vscode) added a bunch of imports, otherwise it is complaining that "TYPE cannot be resolved", so I let it as-is for now, let me know if I should not.

I did separate commits for now, let met know if they should be squashed when you'll be satisfied of the PR.

[lwj5]

Thank you so much @rledisez for your time and effort, the codes look great

@wing328 could you help to allow the rest of the checks to proceed

[lwj5]

@rledisez could you unmark this as draft

[rledisez]

Sure, sorry for that. It's done.

[lwj5]

LGTM. @wing328 I think failure is related to the parallel test issue, but not sure

[wing328]

the circleci failure has been fixed in the master

[wing328]

FYI. I've cherry-pick 6b7d9ff into master as the latest master is the upcoming v7.0.0 release.

[wing328]

@rledisez I've filed #15589 to fix the string comparison.