builder_duration_test.go

package ferrite_test

import (
	"fmt"
	"os"
	"time"

	"github.com/dogmatiq/ferrite"
	. "github.com/dogmatiq/ferrite"
	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("type DurationBuilder", func() {
	var builder *DurationBuilder

	BeforeEach(func() {
		builder = Duration("FERRITE_DURATION", "<desc>")
	})

	AfterEach(func() {
		tearDown()
	})

	It("panics if the name is empty", func() {
		Expect(func() {
			Duration("", "<desc>").Optional()
		}).To(PanicWith("invalid specification: variable name must not be empty"))
	})

	It("panics if the description is empty", func() {
		Expect(func() {
			Duration("FERRITE_DURATION", "").Optional()
		}).To(PanicWith("specification for FERRITE_DURATION is invalid: variable description must not be empty"))
	})

	When("the variable is required", func() {
		When("the value is a valid duration", func() {
			Describe("func Value()", func() {
				It("returns the value", func() {
					os.Setenv("FERRITE_DURATION", "630s")

					v := builder.
						Required().
						Value()

					Expect(v).To(Equal(630 * time.Second))
				})
			})
		})

		When("the value is invalid", func() {
			Describe("func Value()", func() {
				DescribeTable(
					"it panics",
					func(value, expect string) {
						os.Setenv("FERRITE_DURATION", value)

						Expect(func() {
							builder.
								Required().
								Value()
						}).To(PanicWith(expect))
					},
					Entry(
						"missing units",
						"630",
						`value of FERRITE_DURATION (630) is invalid: missing unit`,
					),
					Entry(
						"unknown units",
						"630q",
						`value of FERRITE_DURATION (630q) is invalid: unknown unit "q"`,
					),
					Entry(
						"less than the minimum",
						"0s",
						`value of FERRITE_DURATION (0s) is invalid: too low, expected 1ns or greater`,
					),
				)
			})
		})

		When("the value is empty", func() {
			When("there is a default value", func() {
				Describe("func Value()", func() {
					It("returns the default", func() {
						expect := 10*time.Minute + 30*time.Second

						v := builder.
							WithDefault(expect).
							Required().
							Value()

						Expect(v).To(Equal(expect))
					})
				})
			})

			When("there is no default value", func() {
				Describe("func Value()", func() {
					It("panics", func() {
						Expect(func() {
							builder.
								Required().
								Value()
						}).To(PanicWith(
							"FERRITE_DURATION is undefined and does not have a default value",
						))
					})
				})
			})
		})
	})

	When("the variable is optional", func() {
		When("the value is a valid duration", func() {
			Describe("func Value()", func() {
				It("returns the value", func() {
					os.Setenv("FERRITE_DURATION", "630s")

					v, ok := builder.
						Optional().
						Value()

					Expect(ok).To(BeTrue())
					Expect(v).To(Equal(630 * time.Second))
				})
			})
		})

		When("the value is invalid", func() {
			Describe("func Value()", func() {
				DescribeTable(
					"it panics",
					func(value, expect string) {
						os.Setenv("FERRITE_DURATION", value)

						Expect(func() {
							builder.
								Optional().
								Value()
						}).To(PanicWith(expect))
					},
					Entry(
						"missing units",
						"630",
						`value of FERRITE_DURATION (630) is invalid: missing unit`,
					),
					Entry(
						"unknown units",
						"630q",
						`value of FERRITE_DURATION (630q) is invalid: unknown unit "q"`,
					),
					Entry(
						"less than the minimum",
						"0s",
						`value of FERRITE_DURATION (0s) is invalid: too low, expected 1ns or greater`,
					),
				)
			})
		})

		When("the value is empty", func() {
			When("there is a default value", func() {
				Describe("func Value()", func() {
					It("returns the default", func() {
						expect := 10*time.Minute + 30*time.Second

						v, ok := builder.
							WithDefault(expect).
							Optional().
							Value()

						Expect(ok).To(BeTrue())
						Expect(v).To(Equal(expect))
					})
				})
			})

			When("there is no default value", func() {
				Describe("func Value()", func() {
					It("returns with ok == false", func() {
						_, ok := builder.
							Optional().
							Value()

						Expect(ok).To(BeFalse())
					})
				})
			})
		})
	})

	When("the value is lower than the minimum limit", func() {
		It("panics", func() {
			Expect(func() {
				os.Setenv("FERRITE_DURATION", "1s")

				builder.
					WithMinimum(5 * time.Second).
					Required().
					Value()
			}).To(PanicWith(
				`value of FERRITE_DURATION (1s) is invalid: too low, expected 5s or greater`,
			))
		})
	})

	When("the value is greater than the maximum limit", func() {
		It("panics", func() {
			Expect(func() {
				os.Setenv("FERRITE_DURATION", "10s")

				builder.
					WithMaximum(5 * time.Second).
					Required().
					Value()
			}).To(PanicWith(
				`value of FERRITE_DURATION (10s) is invalid: too high, expected between 1ns and 5s`,
			))
		})
	})
})

func ExampleDuration_required() {
	defer example()()

	v := ferrite.
		Duration("FERRITE_DURATION", "example duration variable").
		Required()

	os.Setenv("FERRITE_DURATION", "630s")
	ferrite.Init()

	fmt.Println("value is", v.Value())

	// Output:
	// value is 10m30s
}

func ExampleDuration_default() {
	defer example()()

	v := ferrite.
		Duration("FERRITE_DURATION", "example duration variable").
		WithDefault(630 * time.Second).
		Required()

	ferrite.Init()

	fmt.Println("value is", v.Value())

	// Output:
	// value is 10m30s
}

func ExampleDuration_optional() {
	defer example()()

	v := ferrite.
		Duration("FERRITE_DURATION", "example duration variable").
		Optional()

	ferrite.Init()

	if x, ok := v.Value(); ok {
		fmt.Println("value is", x)
	} else {
		fmt.Println("value is undefined")
	}

	// Output:
	// value is undefined
}

func ExampleDuration_limits() {
	defer example()()

	v := ferrite.
		Duration("FERRITE_DURATION", "example duration variable").
		WithMinimum(-1 * time.Hour).
		WithMaximum(+1 * time.Hour).
		Required()

	os.Setenv("FERRITE_DURATION", "0h")
	ferrite.Init()

	fmt.Println("value is", v.Value())

	// Output:
	// value is 0s
}

func ExampleDuration_deprecated() {
	defer example()()

	v := ferrite.
		Duration("FERRITE_DURATION", "example duration variable").
		Deprecated()

	os.Setenv("FERRITE_DURATION", "630s")
	ferrite.Init()

	if x, ok := v.DeprecatedValue(); ok {
		fmt.Println("value is", x)
	} else {
		fmt.Println("value is undefined")
	}

	// Output:
	// Environment Variables:
	//
	//  ❯ FERRITE_DURATION  example duration variable  [ 1ns ... ]  ⚠ deprecated variable set to 630s, equivalent to 10m30s
	//
	// value is 10m30s
}