Upgrade urfave/cli to v2 (#614)

* Upgrade cli to v2
* Re-vendor

vendor/github.com/urfave/cli/v2/context.go

@@ -0,0 +1,274 @@
+package cli
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"strings"
+)
+
+// Context is a type that is passed through to
+// each Handler action in a cli application. Context
+// can be used to retrieve context-specific args and
+// parsed command-line options.
+type Context struct {
+	context.Context
+	App           *App
+	Command       *Command
+	shellComplete bool
+	setFlags      map[string]bool
+	flagSet       *flag.FlagSet
+	parentContext *Context
+}
+
+// NewContext creates a new context. For use in when invoking an App or Command action.
+func NewContext(app *App, set *flag.FlagSet, parentCtx *Context) *Context {
+	c := &Context{App: app, flagSet: set, parentContext: parentCtx}
+	if parentCtx != nil {
+		c.Context = parentCtx.Context
+		c.shellComplete = parentCtx.shellComplete
+		if parentCtx.flagSet == nil {
+			parentCtx.flagSet = &flag.FlagSet{}
+		}
+	}
+
+	c.Command = &Command{}
+
+	if c.Context == nil {
+		c.Context = context.Background()
+	}
+
+	return c
+}
+
+// NumFlags returns the number of flags set
+func (c *Context) NumFlags() int {
+	return c.flagSet.NFlag()
+}
+
+// Set sets a context flag to a value.
+func (c *Context) Set(name, value string) error {
+	return c.flagSet.Set(name, value)
+}
+
+// IsSet determines if the flag was actually set
+func (c *Context) IsSet(name string) bool {
+	if fs := lookupFlagSet(name, c); fs != nil {
+		if fs := lookupFlagSet(name, c); fs != nil {
+			isSet := false
+			fs.Visit(func(f *flag.Flag) {
+				if f.Name == name {
+					isSet = true
+				}
+			})
+			if isSet {
+				return true
+			}
+		}
+
+		f := lookupFlag(name, c)
+		if f == nil {
+			return false
+		}
+
+		return f.IsSet()
+	}
+
+	return false
+}
+
+// LocalFlagNames returns a slice of flag names used in this context.
+func (c *Context) LocalFlagNames() []string {
+	var names []string
+	c.flagSet.Visit(makeFlagNameVisitor(&names))
+	return names
+}
+
+// FlagNames returns a slice of flag names used by the this context and all of
+// its parent contexts.
+func (c *Context) FlagNames() []string {
+	var names []string
+	for _, ctx := range c.Lineage() {
+		ctx.flagSet.Visit(makeFlagNameVisitor(&names))
+	}
+	return names
+}
+
+// Lineage returns *this* context and all of its ancestor contexts in order from
+// child to parent
+func (c *Context) Lineage() []*Context {
+	var lineage []*Context
+
+	for cur := c; cur != nil; cur = cur.parentContext {
+		lineage = append(lineage, cur)
+	}
+
+	return lineage
+}
+
+// Value returns the value of the flag corresponding to `name`
+func (c *Context) Value(name string) interface{} {
+	return c.flagSet.Lookup(name).Value.(flag.Getter).Get()
+}
+
+// Args returns the command line arguments associated with the context.
+func (c *Context) Args() Args {
+	ret := args(c.flagSet.Args())
+	return &ret
+}
+
+// NArg returns the number of the command line arguments.
+func (c *Context) NArg() int {
+	return c.Args().Len()
+}
+
+func lookupFlag(name string, ctx *Context) Flag {
+	for _, c := range ctx.Lineage() {
+		if c.Command == nil {
+			continue
+		}
+
+		for _, f := range c.Command.Flags {
+			for _, n := range f.Names() {
+				if n == name {
+					return f
+				}
+			}
+		}
+	}
+
+	if ctx.App != nil {
+		for _, f := range ctx.App.Flags {
+			for _, n := range f.Names() {
+				if n == name {
+					return f
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func lookupFlagSet(name string, ctx *Context) *flag.FlagSet {
+	for _, c := range ctx.Lineage() {
+		if f := c.flagSet.Lookup(name); f != nil {
+			return c.flagSet
+		}
+	}
+
+	return nil
+}
+
+func copyFlag(name string, ff *flag.Flag, set *flag.FlagSet) {
+	switch ff.Value.(type) {
+	case Serializer:
+		_ = set.Set(name, ff.Value.(Serializer).Serialize())
+	default:
+		_ = set.Set(name, ff.Value.String())
+	}
+}
+
+func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
+	visited := make(map[string]bool)
+	set.Visit(func(f *flag.Flag) {
+		visited[f.Name] = true
+	})
+	for _, f := range flags {
+		parts := f.Names()
+		if len(parts) == 1 {
+			continue
+		}
+		var ff *flag.Flag
+		for _, name := range parts {
+			name = strings.Trim(name, " ")
+			if visited[name] {
+				if ff != nil {
+					return errors.New("Cannot use two forms of the same flag: " + name + " " + ff.Name)
+				}
+				ff = set.Lookup(name)
+			}
+		}
+		if ff == nil {
+			continue
+		}
+		for _, name := range parts {
+			name = strings.Trim(name, " ")
+			if !visited[name] {
+				copyFlag(name, ff, set)
+			}
+		}
+	}
+	return nil
+}
+
+func makeFlagNameVisitor(names *[]string) func(*flag.Flag) {
+	return func(f *flag.Flag) {
+		nameParts := strings.Split(f.Name, ",")
+		name := strings.TrimSpace(nameParts[0])
+
+		for _, part := range nameParts {
+			part = strings.TrimSpace(part)
+			if len(part) > len(name) {
+				name = part
+			}
+		}
+
+		if name != "" {
+			*names = append(*names, name)
+		}
+	}
+}
+
+type requiredFlagsErr interface {
+	error
+	getMissingFlags() []string
+}
+
+type errRequiredFlags struct {
+	missingFlags []string
+}
+
+func (e *errRequiredFlags) Error() string {
+	numberOfMissingFlags := len(e.missingFlags)
+	if numberOfMissingFlags == 1 {
+		return fmt.Sprintf("Required flag %q not set", e.missingFlags[0])
+	}
+	joinedMissingFlags := strings.Join(e.missingFlags, ", ")
+	return fmt.Sprintf("Required flags %q not set", joinedMissingFlags)
+}
+
+func (e *errRequiredFlags) getMissingFlags() []string {
+	return e.missingFlags
+}
+
+func checkRequiredFlags(flags []Flag, context *Context) requiredFlagsErr {
+	var missingFlags []string
+	for _, f := range flags {
+		if rf, ok := f.(RequiredFlag); ok && rf.IsRequired() {
+			var flagPresent bool
+			var flagName string
+
+			for _, key := range f.Names() {
+				if len(key) > 1 {
+					flagName = key
+				}
+
+				if context.IsSet(strings.TrimSpace(key)) {
+					flagPresent = true
+				}
+			}
+
+			if !flagPresent && flagName != "" {
+				missingFlags = append(missingFlags, flagName)
+			}
+		}
+	}
+
+	if len(missingFlags) != 0 {
+		return &errRequiredFlags{missingFlags: missingFlags}
+	}
+
+	return nil
+}