Context tests and tweaks around lineage traversal

per feedback on #410

context.go

@@ -13,12 +13,11 @@ import (
 // can be used to retrieve context-specific Args and
 // parsed command-line options.
 type Context struct {
-	App            *App
+	App     *App
-	Command        Command
+	Command Command
-	flagSet        *flag.FlagSet
+
-	setFlags       map[string]bool
+	flagSet       *flag.FlagSet
-	globalSetFlags map[string]bool
+	parentContext *Context
-	parentContext  *Context
 }
 
 // NewContext creates a new context. For use in when invoking an App or Command action.
@@ -117,7 +116,7 @@ func (c *Context) Set(name, value string) error {
 func (c *Context) IsSet(name string) bool {
 	if fs := lookupFlagSet(name, c); fs != nil {
 		isSet := false
-		c.flagSet.Visit(func(f *flag.Flag) {
+		fs.Visit(func(f *flag.Flag) {
 			if f.Name == name {
 				isSet = true
 			}
@@ -146,25 +145,13 @@ func (c *Context) FlagNames() []string {
 	return names
 }
 
-// Parent returns the parent context, if any
-func (c *Context) Parent() *Context {
-	return c.parentContext
-}
-
 // Lineage returns *this* context and all of its ancestor contexts in order from
 // child to parent
 func (c *Context) Lineage() []*Context {
 	lineage := []*Context{}
-	cur := c
 
-	for {
+	for cur := c; cur != nil; cur = cur.parentContext {
 		lineage = append(lineage, cur)
-
-		if cur.parentContext == nil {
-			break
-		}
-
-		cur = cur.parentContext
 	}
 
 	return lineage
@@ -220,19 +207,6 @@ func (a Args) Swap(from, to int) error {
 	return nil
 }
 
-func globalContext(ctx *Context) *Context {
-	if ctx == nil {
-		return nil
-	}
-
-	for {
-		if ctx.parentContext == nil {
-			return ctx
-		}
-		ctx = ctx.parentContext
-	}
-}
-
 func lookupFlagSet(name string, ctx *Context) *flag.FlagSet {
 	for _, c := range ctx.Lineage() {
 		if f := c.flagSet.Lookup(name); f != nil {

context_test.go

@@ -84,18 +84,22 @@ func TestContext_NArg(t *testing.T) {
 
 func TestContext_IsSet(t *testing.T) {
 	set := flag.NewFlagSet("test", 0)
-	set.Bool("myflag", false, "doc")
+	set.Bool("one-flag", false, "doc")
-	set.String("otherflag", "hello world", "doc")
+	set.Bool("two-flag", false, "doc")
-	globalSet := flag.NewFlagSet("test", 0)
+	set.String("three-flag", "hello world", "doc")
-	globalSet.Bool("myflagGlobal", true, "doc")
+	parentSet := flag.NewFlagSet("test", 0)
-	globalCtx := NewContext(nil, globalSet, nil)
+	parentSet.Bool("top-flag", true, "doc")
-	c := NewContext(nil, set, globalCtx)
+	parentCtx := NewContext(nil, parentSet, nil)
-	set.Parse([]string{"--myflag", "bat", "baz"})
+	ctx := NewContext(nil, set, parentCtx)
-	globalSet.Parse([]string{"--myflagGlobal", "bat", "baz"})
+
-	expect(t, c.IsSet("myflag"), true)
+	set.Parse([]string{"--one-flag", "--two-flag", "--three-flag", "frob"})
-	expect(t, c.IsSet("otherflag"), false)
+	parentSet.Parse([]string{"--top-flag"})
-	expect(t, c.IsSet("bogusflag"), false)
+
-	expect(t, c.IsSet("myflagGlobal"), false)
+	expect(t, ctx.IsSet("one-flag"), true)
+	expect(t, ctx.IsSet("two-flag"), true)
+	expect(t, ctx.IsSet("three-flag"), true)
+	expect(t, ctx.IsSet("top-flag"), true)
+	expect(t, ctx.IsSet("bogus"), false)
 }
 
 func TestContext_NumFlags(t *testing.T) {
@@ -124,14 +128,14 @@ func TestContext_LocalFlagNames(t *testing.T) {
 	set := flag.NewFlagSet("test", 0)
 	set.Bool("one-flag", false, "doc")
 	set.String("two-flag", "hello world", "doc")
-	globalSet := flag.NewFlagSet("test", 0)
+	parentSet := flag.NewFlagSet("test", 0)
-	globalSet.Bool("top-flag", true, "doc")
+	parentSet.Bool("top-flag", true, "doc")
-	globalCtx := NewContext(nil, globalSet, nil)
+	parentCtx := NewContext(nil, parentSet, nil)
-	c := NewContext(nil, set, globalCtx)
+	ctx := NewContext(nil, set, parentCtx)
 	set.Parse([]string{"--one-flag", "--two-flag=foo"})
-	globalSet.Parse([]string{"--top-flag"})
+	parentSet.Parse([]string{"--top-flag"})
 
-	actualFlags := c.LocalFlagNames()
+	actualFlags := ctx.LocalFlagNames()
 	sort.Strings(actualFlags)
 
 	expect(t, actualFlags, []string{"one-flag", "two-flag"})
@@ -141,15 +145,52 @@ func TestContext_FlagNames(t *testing.T) {
 	set := flag.NewFlagSet("test", 0)
 	set.Bool("one-flag", false, "doc")
 	set.String("two-flag", "hello world", "doc")
-	globalSet := flag.NewFlagSet("test", 0)
+	parentSet := flag.NewFlagSet("test", 0)
-	globalSet.Bool("top-flag", true, "doc")
+	parentSet.Bool("top-flag", true, "doc")
-	globalCtx := NewContext(nil, globalSet, nil)
+	parentCtx := NewContext(nil, parentSet, nil)
-	c := NewContext(nil, set, globalCtx)
+	ctx := NewContext(nil, set, parentCtx)
 	set.Parse([]string{"--one-flag", "--two-flag=foo"})
-	globalSet.Parse([]string{"--top-flag"})
+	parentSet.Parse([]string{"--top-flag"})
 
-	actualFlags := c.FlagNames()
+	actualFlags := ctx.FlagNames()
 	sort.Strings(actualFlags)
 
 	expect(t, actualFlags, []string{"one-flag", "top-flag", "two-flag"})
 }
+
+func TestContext_Lineage(t *testing.T) {
+	set := flag.NewFlagSet("test", 0)
+	set.Bool("local-flag", false, "doc")
+	parentSet := flag.NewFlagSet("test", 0)
+	parentSet.Bool("top-flag", true, "doc")
+	parentCtx := NewContext(nil, parentSet, nil)
+	ctx := NewContext(nil, set, parentCtx)
+	set.Parse([]string{"--local-flag"})
+	parentSet.Parse([]string{"--top-flag"})
+
+	lineage := ctx.Lineage()
+	expect(t, len(lineage), 2)
+	expect(t, lineage[0], ctx)
+	expect(t, lineage[1], parentCtx)
+}
+
+func TestContext_lookupFlagSet(t *testing.T) {
+	set := flag.NewFlagSet("test", 0)
+	set.Bool("local-flag", false, "doc")
+	parentSet := flag.NewFlagSet("test", 0)
+	parentSet.Bool("top-flag", true, "doc")
+	parentCtx := NewContext(nil, parentSet, nil)
+	ctx := NewContext(nil, set, parentCtx)
+	set.Parse([]string{"--local-flag"})
+	parentSet.Parse([]string{"--top-flag"})
+
+	fs := lookupFlagSet("top-flag", ctx)
+	expect(t, fs, parentCtx.flagSet)
+
+	fs = lookupFlagSet("local-flag", ctx)
+	expect(t, fs, ctx.flagSet)
+
+	if fs := lookupFlagSet("frob", ctx); fs != nil {
+		t.Fail()
+	}
+}