Generate flag types (again?)

Closes urfave#1381

.github/workflows/cli.yml

@@ -87,3 +87,8 @@ jobs:
 
       - name: toc
         run: go run internal/build/build.go toc docs/v2/manual.md
+
+      - name: diff check
+        run: |
+          git diff --exit-code
+          git diff --cached --exit-code

Makefile

@@ -0,0 +1,40 @@
+# NOTE: this Makefile is meant to provide a simplified entry point for humans to
+# run all of the critical steps to verify one's changes are harmonious in
+# nature. Keeping target bodies to one line each and abstaining from make magic
+# are very important so that maintainers and contributors can focus their
+# attention on files that are primarily Go.
+
+.PHONY: all
+all: generate lint tag-test test check-bin tag-check-bin gfmrun toc
+
+.PHONY: generate
+generate:
+	go run internal/build/build.go generate
+
+.PHONY: lint
+lint:
+	go run internal/build/build.go vet
+
+.PHONY: tag-test
+tag-test:
+	go run internal/build/build.go -tags urfave_cli_no_docs test
+
+.PHONY: test
+test:
+	go run internal/build/build.go test
+
+.PHONY: check-bin
+check-bin:
+	go run internal/build/build.go check-binary-size
+
+.PHONY: tag-check-bin
+tag-check-bin:
+	go run internal/build/build.go -tags urfave_cli_no_docs check-binary-size
+
+.PHONY: gfmrun
+gfmrun:
+	go run internal/build/build.go gfmrun docs/v2/manual.md
+
+.PHONY: toc
+toc:
+	go run internal/build/build.go toc docs/v2/manual.md

cli.go

@@ -20,4 +20,4 @@
 //   }
 package cli
 
-//go:generate go run flag-gen/main.go flag-gen/assets_vfsdata.go
+//go:generate go run internal/genflags/cmd/genflags/main.go

docs/CONTRIBUTING.md

@@ -1,18 +1,102 @@
 ## Contributing
 
-Use @urfave/cli to ping the maintainers.
-
-Feel free to put up a pull request to fix a bug or maybe add a feature. We will
-give it a code review and make sure that it does not break backwards
-compatibility. If collaborators agree that it is in line with
-the vision of the project, we will work with you to get the code into
-a mergeable state and merge it into the main branch.
-
-If you have contributed something significant to the project, we will most
-likely add you as a collaborator. As a collaborator you are given the ability
-to merge others pull requests. It is very important that new code does not
-break existing code, so be careful about what code you do choose to merge.
-
-If you feel like you have contributed to the project but have not yet been added
-as a collaborator, we probably forgot to add you :sweat_smile:. Please open an
-issue!
+Welcome to the `urfave/cli` contributor docs! This goal of this document is to help those
+interested in joining the 200+ humans who have contributed to this project over the years.
+
+> As a general guiding principle, the current maintainers may be notified via the
+> @urfave/cli GitHub team.
+
+All of the current maintainers are *volunteers* who live in various timezones with
+different scheduling needs, so please understand that your contribution or question may
+not get a response for many days.
+
+### semantic versioning adherence
+
+The `urfave/cli` project strives to strictly adhere to semantic versioning. The active
+development branches and the milestones and import paths to which they correspond are:
+
+#### `main` branch
+
+<https://github.com/urfave/cli/tree/main>
+
+The majority of active development and issue management is targeting the `main` branch,
+which **MUST** *only* receive bug fixes and feature *additions*.
+
+- :arrow_right: [`v2.x`](https://github.com/urfave/cli/milestone/16)
+- :arrow_right: `github.com/urfave/cli/v2`
+
+#### `v1` branch
+
+<https://github.com/urfave/cli/tree/v1>
+
+The `v1` branch **MUST** only receive bug fixes in the `v1.22.x` series. There is no
+strict rule regarding bug fixes to the `v2.x` series being backported to the `v1.22.x`
+series.
+
+- :arrow_right: [`v1.22.x`](https://github.com/urfave/cli/milestone/11)
+- :arrow_right: `github.com/urfave/cli`
+
+#### `v3-dev-main` branch
+
+<https://github.com/urfave/cli/tree/v3-dev-main>
+
+The `v3-dev-branch` **MUST** receive all bug fixes and features added to the `main` branch
+and **MAY** receive feature *removals* and other changes that are otherwise
+*backward-incompatible* with the `v2.x` series.
+
+- :arrow_right: [`v3.x`](https://github.com/urfave/cli/milestone/5)
+- unreleased / unsupported
+
+### development workflow
+
+Most of the tooling around the development workflow strives for effective
+[dogfooding](https://en.wikipedia.org/wiki/Eating_your_own_dog_food). There is a top-level
+`Makefile` that is maintained strictly for the purpose of easing verification of one's
+development environment and any changes one may have introduced:
+
+```sh
+make
+```
+
+Running the default `make` target (`all`) will ensure all of the critical steps are run to
+verify one's changes are harmonious in nature. The same steps are also run during the
+[continuous integration
+phase](https://github.com/urfave/cli/blob/main/.github/workflows/cli.yml).
+
+#### generated code
+
+A significant portion of the project's source code is generated, with the goal being to
+eliminate repetetive maintenance where other type-safe abstraction is impractical or
+impossible with Go versions `< 1.18`. In a future where the eldest Go version supported is
+`1.18.x`, there will likely be efforts to take advantage of
+[generics](https://go.dev/doc/tutorial/generics).
+
+The built-in `go generate` command is used to run the commands specified in
+`//go:generate` directives. Each such command runs a file that also supports a command
+line help system which may be consulted for further information, e.g.:
+
+```sh
+go run internal/genflags/cmd/genflags/main.go --help
+```
+
+### pull requests
+
+Please feel free to open a pull request to fix a bug or add a feature. The @urfave/cli
+team will review it as soon as possible, giving special attention to maintaining backward
+compatibility. If the @urfave/cli team agrees that your contribution is in line with the
+vision of the project, they will work with you to get the code into a mergeable state,
+merged, and then released.
+
+### granting of commit bit / admin mode
+
+Those with a history of contributing to this project will likely be invited to join the
+@urfave/cli team. As a member of the @urfave/cli team, you will have the ability to fully
+administer pull requests, issues, and other repository bits.
+
+If you feel that you should be a member of the @urfave/cli team but have not yet been
+added, the most likely explanation is that this is an accidental oversight! :sweat_smile:.
+Please open an issue!
+
+<!--
+vim:tw=90
+-->

flag-spec.yaml

@@ -0,0 +1,50 @@
+# NOTE: this file is used by the tool defined in
+# ./internal/genflags/cmd/genflags/main.go which uses the
+# `genflags.Spec` type that maps to this file structure.
+
+flag_types:
+  bool: {}
+  float64: {}
+  int64: {}
+  int: {}
+  time.Duration: {}
+  uint64: {}
+  uint: {}
+
+  string:
+    struct_fields:
+      - { name: TakesFile, type: bool }
+  Generic:
+    struct_fields:
+      - { name: TakesFile, type: bool }
+  Path:
+    struct_fields:
+      - { name: TakesFile, type: bool }
+
+  Float64Slice:
+    value_pointer: true
+    skip_interfaces:
+      - fmt.Stringer
+  Int64Slice:
+    value_pointer: true
+    skip_interfaces:
+      - fmt.Stringer
+  IntSlice:
+    value_pointer: true
+    skip_interfaces:
+      - fmt.Stringer
+  StringSlice:
+    value_pointer: true
+    skip_interfaces:
+      - fmt.Stringer
+    struct_fields:
+      - { name: TakesFile, type: bool }
+  Timestamp:
+    value_pointer: true
+    struct_fields:
+      - { name: Layout, type: string }
+
+  # TODO: enable UintSlice
+  # UintSlice: {}
+  # TODO: enable Uint64Slice once #1334 lands
+  # Uint64Slice: {}

flag.go

@@ -258,7 +258,7 @@ func withEnvHint(envVars []string, str string) string {
 	return str + envText
 }
 
-func flagNames(name string, aliases []string) []string {
+func FlagNames(name string, aliases []string) []string {
 	var ret []string
 
 	for _, part := range append([]string{name}, aliases...) {

flag_bool.go

@@ -6,37 +6,6 @@ import (
 	"strconv"
 )
 
-// BoolFlag is a flag with type bool
-type BoolFlag struct {
-	Name        string
-	Aliases     []string
-	Usage       string
-	EnvVars     []string
-	FilePath    string
-	Required    bool
-	Hidden      bool
-	Value       bool
-	DefaultText string
-	Destination *bool
-	HasBeenSet  bool
-}
-
-// IsSet returns whether or not the flag has been set through env or file
-func (f *BoolFlag) IsSet() bool {
-	return f.HasBeenSet
-}
-
-// String returns a readable representation of this value
-// (for usage defaults)
-func (f *BoolFlag) String() string {
-	return FlagStringer(f)
-}
-
-// Names returns the names of the flag
-func (f *BoolFlag) Names() []string {
-	return flagNames(f.Name, f.Aliases)
-}
-
 // IsRequired returns whether or not the flag is required
 func (f *BoolFlag) IsRequired() bool {
 	return f.Required

flag_duration.go

@@ -6,37 +6,6 @@ import (
 	"time"
 )
 
-// DurationFlag is a flag with type time.Duration (see https://golang.org/pkg/time/#ParseDuration)
-type DurationFlag struct {
-	Name        string
-	Aliases     []string
-	Usage       string
-	EnvVars     []string
-	FilePath    string
-	Required    bool
-	Hidden      bool
-	Value       time.Duration
-	DefaultText string
-	Destination *time.Duration
-	HasBeenSet  bool
-}
-
-// IsSet returns whether or not the flag has been set through env or file
-func (f *DurationFlag) IsSet() bool {
-	return f.HasBeenSet
-}
-
-// String returns a readable representation of this value
-// (for usage defaults)
-func (f *DurationFlag) String() string {
-	return FlagStringer(f)
-}
-
-// Names returns the names of the flag
-func (f *DurationFlag) Names() []string {
-	return flagNames(f.Name, f.Aliases)
-}
-
 // IsRequired returns whether or not the flag is required
 func (f *DurationFlag) IsRequired() bool {
 	return f.Required

flag_float64.go

@@ -6,37 +6,6 @@ import (
 	"strconv"
 )
 
-// Float64Flag is a flag with type float64
-type Float64Flag struct {
-	Name        string
-	Aliases     []string
-	Usage       string
-	EnvVars     []string
-	FilePath    string
-	Required    bool
-	Hidden      bool
-	Value       float64
-	DefaultText string
-	Destination *float64
-	HasBeenSet  bool
-}
-
-// IsSet returns whether or not the flag has been set through env or file
-func (f *Float64Flag) IsSet() bool {
-	return f.HasBeenSet
-}
-
-// String returns a readable representation of this value
-// (for usage defaults)
-func (f *Float64Flag) String() string {
-	return FlagStringer(f)
-}
-
-// Names returns the names of the flag
-func (f *Float64Flag) Names() []string {
-	return flagNames(f.Name, f.Aliases)
-}
-
 // IsRequired returns whether or not the flag is required
 func (f *Float64Flag) IsRequired() bool {
 	return f.Required

flag_float64_slice.go

@@ -75,36 +75,12 @@ func (f *Float64Slice) Get() interface{} {
 	return *f
 }
 
-// Float64SliceFlag is a flag with type *Float64Slice
-type Float64SliceFlag struct {
-	Name        string
-	Aliases     []string
-	Usage       string
-	EnvVars     []string
-	FilePath    string
-	Required    bool
-	Hidden      bool
-	Value       *Float64Slice
-	DefaultText string
-	HasBeenSet  bool
-}
-
-// IsSet returns whether or not the flag has been set through env or file
-func (f *Float64SliceFlag) IsSet() bool {
-	return f.HasBeenSet
-}
-
 // String returns a readable representation of this value
 // (for usage defaults)
 func (f *Float64SliceFlag) String() string {
 	return withEnvHint(f.GetEnvVars(), stringifyFloat64SliceFlag(f))
 }
 
-// Names returns the names of the flag
-func (f *Float64SliceFlag) Names() []string {
-	return flagNames(f.Name, f.Aliases)
-}
-
 // IsRequired returns whether or not the flag is required
 func (f *Float64SliceFlag) IsRequired() bool {
 	return f.Required