Fix to generate validations of hash elements

[ikawaha]

HashOf accepts optional DSLs as third and fourth argument which allows providing validations for the keys and values of the hash. But there is no validation codes generated.

Sample design:

package design

import (
	. "github.com/goadesign/goa/design"
	. "github.com/goadesign/goa/design/apidsl"
)

var _ = API("cellar", func() {
	Title("The virtual wine cellar")
	Description("A simple goa service")
	Scheme("http")
	Host("localhost:8080")
})

var Bottle = Type("bottle", func() {
	Param("names", ArrayOf(String, func() {
		Pattern("[a-zA-Z]+")
	}))
	Param("bottles", HashOf(String, String, func() {
		Pattern("[a-zA-Z]+")
	}, func() {
		Pattern("[0-9]+")
	}), func() {
		MinLength(1)
	})
})

var _ = Resource("bottle", func() {
	BasePath("/bottles")
	DefaultMedia(BottleMedia)

	Action("show", func() {
		Description("Get bottle by id")
		Routing(GET("/:bottleID"))
		Params(func() {
			Param("bottleID", Integer, "Bottle ID")
		})
		Response(OK)
		Response(NotFound)
	})
	Action("updateRatings", func() {
		Routing(POST(""))
		Payload(func() {
			Member("validatableHash", HashOf(String, Integer, func() {
				Pattern("[a-zA-Z]+")
			}, func() {
				Enum(12, 3, 4, 5, 6)
			}))
			Member("validatableArray", ArrayOf(String, func() {
				Pattern("[a-zA-Z]+")
			}))
		})
	})
})

var BottleMedia = MediaType("application/vnd.goa.example.bottle+json", func() {
	Description("A bottle of wine")
	Attributes(func() {
		Attribute("id", Integer, "Unique bottle ID")
		Attribute("href", String, "API href for making requests on the bottle")
		Attribute("name", String, "Name of wine")
		Required("id", "href", "name")
	})
	View("default", func() {
		Attribute("id")
		Attribute("href")
		Attribute("name")
	})
})

Above design generates following codes:

app/contexts.go

// Validate runs the validation rules defined in the design.
func (payload *UpdateRatingsBottlePayload) Validate() (err error) {
        for _, e := range payload.ValidatableArray {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, e); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`raw.validatableArray[*]`, e, `[a-zA-Z]+`))
                }
                // ← ★ hash validation codes should be here !!!
        }
        return
}

app/user_type.go

// Validate validates the Bottle type instance.
func (ut *Bottle) Validate() (err error) {
        if ut.Bottles != nil {
                if len(ut.Bottles) < 1 {
                        err = goa.MergeErrors(err, goa.InvalidLengthError(`response.bottles`, ut.Bottles, len(ut.Bottles), 1, true))
                }
        }
        for _, e := range ut.Names {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, e); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`response.names[*]`, e, `[a-zA-Z]+`))
                }
        }

        // ← ★ hash validation codes should be here !!!

        return
}

This patch is applied:

app/contexts.go

// Validate runs the validation rules defined in the design.
func (payload *UpdateRatingsBottlePayload) Validate() (err error) {
        for _, e := range payload.ValidatableArray {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, e); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`raw.validatableArray[*]`, e, `[a-zA-Z]+`))
                }
        }
        for k, e := range payload.ValidatableHash {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, k); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`raw.validatableHash[*]`, k, `[a-zA-Z]+`))
                }
                if !(e == 12 || e == 3 || e == 4 || e == 5 || e == 6) {
                        err = goa.MergeErrors(err, goa.InvalidEnumValueError(`raw.validatableHash[*]`, e, []interface{}{12, 3, 4,
5, 6}))
                }
        }
        return
}

app/user_type.go

// Validate validates the Bottle type instance.
func (ut *Bottle) Validate() (err error) {
        if ut.Bottles != nil {
                if len(ut.Bottles) < 1 {
                        err = goa.MergeErrors(err, goa.InvalidLengthError(`response.bottles`, ut.Bottles, len(ut.Bottles), 1, true
))
                }
        }
        for k, e := range ut.Bottles {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, k); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`response.bottles[*]`, k, `[a-zA-Z]+`))
                }
                if ok := goa.ValidatePattern(`[0-9]+`, e); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`response.bottles[*]`, e, `[0-9]+`))
                }
        }
        for _, e := range ut.Names {
                if ok := goa.ValidatePattern(`[a-zA-Z]+`, e); !ok {
                        err = goa.MergeErrors(err, goa.InvalidPatternError(`response.names[*]`, e, `[a-zA-Z]+`))
                }
        }
        return
}

[raphael]

Thank you for doing that! I left a couple of questions in the review.

[ikawaha]

Thank you for your review. I misunderstood the specification.
I fixed the part pointed out in the review.

[raphael]

Awesome PR, thank you! Do you think you could backport to v1?