color/internal/helper/model_test.go

package helper

import (
	"image/color"
	"testing"
)

func eq[T comparable](a, b T) bool {
	return a == b
}

type nrgba64 struct {
	color.NRGBA64
}

func (c *nrgba64) set(v color.NRGBA64) {
	c.NRGBA64 = v
}

func (c nrgba64) NRGBA() (_, _, _, _ uint32) {
	return uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
}

func (c nrgba64) NLRGBA() (_, _, _, _ float64) {
	return NRGBAtoNLRGBA(c.NRGBA())
}

func (c nrgba64) NXYZA() (_, _, _, _ float64) {
	r, g, b, a := c.NLRGBA()
	x, y, z := LRGBtoXYZ(r, g, b)
	return x, y, z, a
}

func (c nrgba64) NOkLabA() (_, _, _, _ float64) {
	r, g, b, a := c.NLRGBA()
	lightness, chromaA, chromaB := LMStoOkLab(LRGBtoLMS(r, g, b))
	return lightness, chromaA, chromaB, a
}

func convert[C Color, P interface {
	*C
	set(color.NRGBA64)
}](c color.Color) C {
	var result C
	P(&result).set(color.NRGBA64Model.Convert(c).(color.NRGBA64))
	return result
}

type nrgba64BadRGBA struct {
	nrgba64
}

func (nrgba64BadRGBA) RGBA() (_, _, _, _ uint32) {
	return 1, 2, 3, 4
}

type nrgba64BadNRGBA struct {
	nrgba64
}

func (nrgba64BadNRGBA) NRGBA() (_, _, _, _ uint32) {
	return 1, 2, 3, 4
}

type nrgba64BadNLRGBA struct {
	nrgba64
}

func (nrgba64BadNLRGBA) NLRGBA() (_, _, _, _ float64) {
	return 1, 2, 3, 4
}

type nrgba64BadNXYZA struct {
	nrgba64
}

func (nrgba64BadNXYZA) NXYZA() (_, _, _, _ float64) {
	return 1, 2, 3, 4
}

type nrgba64BadNOkLabA struct {
	nrgba64
}

func (nrgba64BadNOkLabA) NOkLabA() (_, _, _, _ float64) {
	return 1, 2, 3, 4
}

func TestTestModel(t *testing.T) {
	mt := mockTester{t: t}

	mt.run("wrong colour type", func(t *mockTest) {
		TestModel(t, true, true, color.RGBAModel, eq[nrgba64], nil)
	})

	mt.run("bad RGBA", func(t *mockTest) {
		TestModel(t, true, false, Model(convert[nrgba64BadRGBA]), eq[nrgba64BadRGBA], nil)
	})

	mt.run("bad NRGBA", func(t *mockTest) {
		TestModel(t, true, false, Model(convert[nrgba64BadNRGBA]), eq[nrgba64BadNRGBA], nil)
	})

	mt.run("bad NLRGBA", func(t *mockTest) {
		TestModel(t, true, false, Model(convert[nrgba64BadNLRGBA]), eq[nrgba64BadNLRGBA], nil)
	})

	mt.run("bad NXYZA", func(t *mockTest) {
		TestModel(t, true, false, Model(convert[nrgba64BadNXYZA]), eq[nrgba64BadNXYZA], nil)
	})

	mt.run("bad NOkLabA", func(t *mockTest) {
		TestModel(t, true, false, Model(convert[nrgba64BadNOkLabA]), eq[nrgba64BadNOkLabA], nil)
	})

	mt.run("working model", func(t *mockTest) {
		TestModel(t, true, true, Model(convert[nrgba64]), eq[nrgba64], []ConvertTest[nrgba64]{
			{"good", color.NRGBA64{0x0123, 0x4567, 0x89ab, 0xcdef}, nrgba64{color.NRGBA64{0x0123, 0x4567, 0x89ab, 0xcdef}}},
			{"bad", color.NRGBA64{0xcafe, 0xf00d, 0x54ac, 0xce55}, nrgba64{color.NRGBA64{0x0123, 0x4567, 0x89ab, 0xcdef}}},
		})
	})

	mt.expectFailedChildren("wrong colour type")
	mt.expectError(
		"wrong colour type/legal colours",
		`model.Convert(color.RGBA64{R:0x0, G:0x0, B:0x0, A:0x0}) returned color.RGBA, expected helper.nrgba64`,
	)

	mt.expectFailedChildren("bad RGBA")
	mt.expectError(
		"bad RGBA/legal colours",
		`helper.nrgba64BadRGBA{nrgba64:helper.nrgba64{NRGBA64:color.NRGBA64{R:0x0, G:0x0, B:0x0, A:0xffff}}}.RGBA() = {1 2 3 4}, want {0 0 0 65535}`,
	)

	mt.expectFailedChildren("bad NRGBA")
	mt.expectError(
		"bad NRGBA/legal colours",
		`helper.nrgba64BadNRGBA{nrgba64:helper.nrgba64{NRGBA64:color.NRGBA64{R:0x0, G:0x0, B:0x0, A:0xffff}}}.NRGBA() = {1 2 3 4}, want {0 0 0 65535}`,
	)

	mt.expectFailedChildren("bad NLRGBA")
	mt.expectError(
		"bad NLRGBA/legal colours",
		`helper.nrgba64BadNLRGBA{nrgba64:helper.nrgba64{NRGBA64:color.NRGBA64{R:0x0, G:0x0, B:0x0, A:0xffff}}}.NLRGBA() = [1 2 3 4], want [0 0 0 1]`,
	)

	mt.expectFailedChildren("bad NXYZA")
	mt.expectError(
		"bad NXYZA/legal colours",
		`helper.nrgba64BadNXYZA{nrgba64:helper.nrgba64{NRGBA64:color.NRGBA64{R:0x0, G:0x0, B:0x0, A:0xffff}}}.NXYZA() = [1 2 3 4] want [0 0 0 1]`,
	)

	mt.expectFailedChildren("bad NOkLabA")
	mt.expectError(
		"bad NOkLabA/legal colours",
		`helper.nrgba64BadNOkLabA{nrgba64:helper.nrgba64{NRGBA64:color.NRGBA64{R:0x0, G:0x0, B:0x0, A:0xffff}}}.NOkLabA()[:3] = [1 2 3 4] want [0 0 0 1]`,
	)

	mt.expectFailedChildren("working model")
	mt.expectSuccess("working model/legal colours")
	mt.expectSuccess("working model/good")
	mt.expectError(
		"working model/bad",
		`model.Convert(color.NRGBA64{R:0xcafe, G:0xf00d, B:0x54ac, A:0xce55}) = helper.nrgba64{NRGBA64:color.NRGBA64{R:0xcafe, G:0xf00d, B:0x54ac, A:0xce55}}, want helper.nrgba64{NRGBA64:color.NRGBA64{R:0x123, G:0x4567, B:0x89ab, A:0xcdef}}`,
	)

	mt.expectAllHandled()
}