From bd2be279a735f287234981c325db3676f4221529 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Tue, 11 Feb 2020 16:55:20 +0100
Subject: [PATCH 1/7] feat(args): add support for empty slice un/marshahaling

---
 internal/args/errors.go         |  9 ++++++++
 internal/args/marshal.go        |  6 +++++
 internal/args/marshal_test.go   | 18 ++++++++++++++-
 internal/args/unmarshal.go      | 41 ++++++++++++++++++++++++++++++---
 internal/args/unmarshal_test.go | 29 +++++++++++++++++++++++
 5 files changed, 99 insertions(+), 4 deletions(-)

diff --git a/internal/args/errors.go b/internal/args/errors.go
index 5bb245a487..91e673f13f 100644
--- a/internal/args/errors.go
+++ b/internal/args/errors.go
@@ -161,6 +161,15 @@ func (e *CannotUnmarshalError) Error() string {
 	return fmt.Sprintf("%T is not unmarshalable: %s", e.Dest, e.Err)
 }
 
+type ConflictArgError struct {
+	ArgName1 string
+	ArgName2 string
+}
+
+func (e *ConflictArgError) Error() string {
+	return fmt.Sprintf("arguments '%s' and '%s' cannot be used simultaneously", e.ArgName1, e.ArgName2)
+}
+
 // missingIndices returns a string of all the missing indices between index and length.
 // e.g.: missingIndices(index=5, length=0) should return "0,1,2,3"
 // e.g.: missingIndices(index=5, length=2) should return "2,3"
diff --git a/internal/args/marshal.go b/internal/args/marshal.go
index 42c3b6c2f9..6dd45f440b 100644
--- a/internal/args/marshal.go
+++ b/internal/args/marshal.go
@@ -123,6 +123,12 @@ func marshal(src reflect.Value, keys []string) (args []string, err error) {
 
 	case reflect.Slice:
 		// If type is a slice:
+
+		// If we explicitly try to marshal a non-nil empty slice we marshal it as args=none
+		if src.Len() == 0 && !src.IsNil() {
+			return append(args, marshalKeyValue(keys, "none")), nil
+		}
+
 		// We loop through all items and marshal them with key = key.0, key.1, ....
 		args := []string(nil)
 		for i := 0; i < src.Len(); i++ {
diff --git a/internal/args/marshal_test.go b/internal/args/marshal_test.go
index eb589ebe09..712b49e145 100644
--- a/internal/args/marshal_test.go
+++ b/internal/args/marshal_test.go
@@ -101,6 +101,17 @@ func TestMarshal(t *testing.T) {
 		},
 	}))
 
+	t.Run("empty-slice", run(TestCase{
+		data: &Slice{
+			Strings:    []string{},
+			StringsPtr: []*string{},
+		},
+		expected: []string{
+			"strings=none",
+			"strings-ptr=none",
+		},
+	}))
+
 	t.Run("well-known-types", run(TestCase{
 		data: &WellKnownTypes{
 			Size: 20 * scw.GB,
@@ -247,11 +258,16 @@ func TestMarshalValue(t *testing.T) {
 		expected: "",
 	}))
 
-	t.Run("typed-nil", run(TestCase{
+	t.Run("nil-slice", run(TestCase{
 		data:     []string(nil),
 		expected: "",
 	}))
 
+	t.Run("empty-slice", run(TestCase{
+		data:     []string{},
+		expected: "none",
+	}))
+
 	t.Run("custom-func", run(TestCase{
 		data:     height(42),
 		expected: "42cm",
diff --git a/internal/args/unmarshal.go b/internal/args/unmarshal.go
index 7dec290a38..b1d0f3041f 100644
--- a/internal/args/unmarshal.go
+++ b/internal/args/unmarshal.go
@@ -75,6 +75,7 @@ func UnmarshalStruct(args []string, data interface{}) error {
 	// Loop through all arguments
 	for _, kv := range argsSlice {
 		argName, argValue := kv[0], kv[1]
+		argNameWords := strings.Split(argName, ".")
 
 		// Make sure argument name is correct.
 		// We enforce this check to avoid not well formatted argument name to work by "accident"
@@ -102,10 +103,39 @@ func UnmarshalStruct(args []string, data interface{}) error {
 				Err:      &DuplicateArgError{},
 			}
 		}
+
+		// We check that we did not already handle an argument value set on a parent
+		// Example `cluster.volume.size=12 cluster=premium` cannot be valid as both args are in conflict.
+		// We loop through all possible parent and check that they are not present in processedArgNames
+		// If argName=cluster.volume.0.size we will check ["cluster", "cluster.volume" "cluster.volume.0"]
+		// Duplicate args are handle above.
+		for index := range argNameWords {
+			processedArgName := strings.Join(argNameWords[:index+1], ".")
+			if processedArgNames[processedArgName] {
+				return &ConflictArgError{
+					ArgName1: processedArgName,
+					ArgName2: argName,
+				}
+			}
+		}
+
+		// We check that we did not already handle an argument value set on a child
+		// Example `cluster=premium cluster.volume.size=12` cannot be valid as both args are in conflict.
+		// We loop through all processedArgNames and if argName starts we one of them we consider it as duplicate
+		// If processedArgNames=["cluster"] and argName=cluster.volume.size we return an error because `cluster.volume.size` as `cluster.` prefix
+		for processedArgName := range processedArgNames {
+			if strings.HasPrefix(processedArgName+".", argName) {
+				return &ConflictArgError{
+					ArgName1: processedArgName,
+					ArgName2: argName,
+				}
+			}
+		}
+
 		processedArgNames[argName] = true
 
 		// Set will recursively find the correct field to set.
-		err := set(dest, strings.Split(argName, "."), argValue)
+		err := set(dest, argNameWords, argValue)
 		if err != nil {
 			return &UnmarshalArgError{
 				ArgName:  argName,
@@ -177,14 +207,19 @@ func set(dest reflect.Value, argNameWords []string, value string) error {
 
 	case reflect.Slice:
 		// If type is a slice:
-		// We check if argNameWords[0] is an number to handle cases like keys.0.value=12
+
+		// We handle special case where array=none creates an empty slice.
+		if len(argNameWords) == 0 && value == "none" {
+			dest.Set(reflect.MakeSlice(dest.Type(), 0, 0))
+			return nil
+		}
 
 		// We cannot handle slice without an index notation.
 		if len(argNameWords) == 0 {
 			return &MissingIndexOnArrayError{}
 		}
 
-		// Make sure index is a positive integer.
+		// We check if argNameWords[0] is an positive integer to handle cases like keys.0.value=12
 		index, err := strconv.ParseUint(argNameWords[0], 10, 64)
 		if err != nil {
 			return &InvalidIndexError{Index: argNameWords[0]}
diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index e34e56cacc..e38133331b 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -185,6 +185,35 @@ func TestUnmarshalStruct(t *testing.T) {
 		},
 	}))
 
+	t.Run("empty-slice", run(TestCase{
+		args: []string{
+			"strings=none",
+			"strings-ptr=none",
+		},
+		expected: &Slice{
+			Strings:    []string{},
+			StringsPtr: []*string{},
+		},
+	}))
+
+	t.Run("simple-parent-child-conflict", run(TestCase{
+		args: []string{
+			"strings=none",
+			"strings.0=none",
+		},
+		error: "arguments 'strings' and 'strings.0' cannot be used simultaneously",
+		data:  &Slice{},
+	}))
+
+	t.Run("simple-child-parent-conflict", run(TestCase{
+		args: []string{
+			"strings.0=none",
+			"strings=none",
+		},
+		error: "arguments 'strings.0' and 'strings' cannot be used simultaneously",
+		data:  &Slice{},
+	}))
+
 	t.Run("well-known-types", run(TestCase{
 		args: []string{
 			"size=20gb",

From 6650b77715690e7b160c664e16e4c4a0c2fe206e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Tue, 11 Feb 2020 16:57:24 +0100
Subject: [PATCH 2/7] add const

---
 internal/args/args.go      | 2 ++
 internal/args/marshal.go   | 2 +-
 internal/args/unmarshal.go | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/internal/args/args.go b/internal/args/args.go
index 595e3ac15f..abd818bc1c 100644
--- a/internal/args/args.go
+++ b/internal/args/args.go
@@ -9,6 +9,8 @@ import (
 // validArgNameRegex regex to check that args words are lower-case or digit starting and ending with a letter.
 var validArgNameRegex = regexp.MustCompile(`^([a-z][a-z0-9-]*)(\.[a-z0-9-]*)*$`)
 
+const emptySliceValue = "none"
+
 // RawArgs allows to retrieve a simple []string using UnmarshalStruct()
 type RawArgs []string
 
diff --git a/internal/args/marshal.go b/internal/args/marshal.go
index 6dd45f440b..4a3467be00 100644
--- a/internal/args/marshal.go
+++ b/internal/args/marshal.go
@@ -126,7 +126,7 @@ func marshal(src reflect.Value, keys []string) (args []string, err error) {
 
 		// If we explicitly try to marshal a non-nil empty slice we marshal it as args=none
 		if src.Len() == 0 && !src.IsNil() {
-			return append(args, marshalKeyValue(keys, "none")), nil
+			return append(args, marshalKeyValue(keys, emptySliceValue)), nil
 		}
 
 		// We loop through all items and marshal them with key = key.0, key.1, ....
diff --git a/internal/args/unmarshal.go b/internal/args/unmarshal.go
index b1d0f3041f..1a22f0741e 100644
--- a/internal/args/unmarshal.go
+++ b/internal/args/unmarshal.go
@@ -209,7 +209,7 @@ func set(dest reflect.Value, argNameWords []string, value string) error {
 		// If type is a slice:
 
 		// We handle special case where array=none creates an empty slice.
-		if len(argNameWords) == 0 && value == "none" {
+		if len(argNameWords) == 0 && value == emptySliceValue {
 			dest.Set(reflect.MakeSlice(dest.Type(), 0, 0))
 			return nil
 		}

From fb6ccacd7b818a91271498111c9c0f9c42797f87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Thu, 13 Feb 2020 12:01:31 +0100
Subject: [PATCH 3/7] fix test

---
 internal/args/args_test.go      |  5 +++++
 internal/args/unmarshal.go      | 31 +++++++++++--------------------
 internal/args/unmarshal_test.go | 11 +++++++++++
 3 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/internal/args/args_test.go b/internal/args/args_test.go
index c05f734550..445fea1d32 100644
--- a/internal/args/args_test.go
+++ b/internal/args/args_test.go
@@ -129,3 +129,8 @@ func unmarshalHeight(value string, dest interface{}) error {
 	_, err := fmt.Sscanf(value, "%dcm", h)
 	return err
 }
+
+type SamePrefixArgName struct {
+	IP   string
+	IPv6 string
+}
diff --git a/internal/args/unmarshal.go b/internal/args/unmarshal.go
index 1a22f0741e..cbd7f3b3e9 100644
--- a/internal/args/unmarshal.go
+++ b/internal/args/unmarshal.go
@@ -104,34 +104,25 @@ func UnmarshalStruct(args []string, data interface{}) error {
 			}
 		}
 
-		// We check that we did not already handle an argument value set on a parent
-		// Example `cluster.volume.size=12 cluster=premium` cannot be valid as both args are in conflict.
-		// We loop through all possible parent and check that they are not present in processedArgNames
-		// If argName=cluster.volume.0.size we will check ["cluster", "cluster.volume" "cluster.volume.0"]
-		// Duplicate args are handle above.
-		for index := range argNameWords {
-			processedArgName := strings.Join(argNameWords[:index+1], ".")
-			if processedArgNames[processedArgName] {
-				return &ConflictArgError{
-					ArgName1: processedArgName,
-					ArgName2: argName,
-				}
-			}
-		}
-
-		// We check that we did not already handle an argument value set on a child
+		// We check that we did not already handle an argument value set on a child or a parent
 		// Example `cluster=premium cluster.volume.size=12` cannot be valid as both args are in conflict.
-		// We loop through all processedArgNames and if argName starts we one of them we consider it as duplicate
-		// If processedArgNames=["cluster"] and argName=cluster.volume.size we return an error because `cluster.volume.size` as `cluster.` prefix
+		// Example `cluster.volume.size=12 cluster=premium` should also be invalid.
 		for processedArgName := range processedArgNames {
-			if strings.HasPrefix(processedArgName+".", argName) {
+			// We put the longest argName in long and the shortest in short.
+			short, long := argName, processedArgName
+			if len(long) < len(short) {
+				short, long = long, short
+			}
+
+			// We check if the longest starts with short+"."
+			// If it does this mean we have a conflict.
+			if strings.HasPrefix(long, short+".") {
 				return &ConflictArgError{
 					ArgName1: processedArgName,
 					ArgName2: argName,
 				}
 			}
 		}
-
 		processedArgNames[argName] = true
 
 		// Set will recursively find the correct field to set.
diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index e38133331b..46a38b25b6 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -408,6 +408,17 @@ func TestUnmarshalStruct(t *testing.T) {
 	}))
 }
 
+	t.Run("common-prefix-args", run(TestCase{
+		args: []string{
+			"ip=ip",
+			"ipv6=ipv6",
+		},
+		expected: &SamePrefixArgName{
+			IP:   "ip",
+			IPv6: "ipv6",
+		},
+	}))
+}
 func TestIsUmarshalableValue(t *testing.T) {
 	type TestCase struct {
 		expected bool

From 59f948b99e2e997b786bda6bbaf43cbb624baf17 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Thu, 13 Feb 2020 13:47:44 +0100
Subject: [PATCH 4/7] address comments

---
 internal/args/args_test.go      | 1 +
 internal/args/errors.go         | 2 ++
 internal/args/marshal_test.go   | 8 ++++++++
 internal/args/unmarshal.go      | 4 ++--
 internal/args/unmarshal_test.go | 8 ++++++++
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/internal/args/args_test.go b/internal/args/args_test.go
index 445fea1d32..1ff49f3520 100644
--- a/internal/args/args_test.go
+++ b/internal/args/args_test.go
@@ -25,6 +25,7 @@ type Basic struct {
 type Slice struct {
 	Strings    []string
 	StringsPtr []*string
+	SlicePtr   *[]string
 	Basics     []Basic
 }
 
diff --git a/internal/args/errors.go b/internal/args/errors.go
index 91e673f13f..b824c0a237 100644
--- a/internal/args/errors.go
+++ b/internal/args/errors.go
@@ -161,6 +161,8 @@ func (e *CannotUnmarshalError) Error() string {
 	return fmt.Sprintf("%T is not unmarshalable: %s", e.Dest, e.Err)
 }
 
+// ConflictArgError is return when two args that are in conflict with each other are used together.
+// e.g cluster=prod cluster.name=test are conflicting args
 type ConflictArgError struct {
 	ArgName1 string
 	ArgName2 string
diff --git a/internal/args/marshal_test.go b/internal/args/marshal_test.go
index 712b49e145..b1cb5afa8e 100644
--- a/internal/args/marshal_test.go
+++ b/internal/args/marshal_test.go
@@ -15,6 +15,8 @@ func TestMarshal(t *testing.T) {
 	}
 
 	stringPtr := "test"
+	slicePtr := []string{"0", "1", "2"}
+	emptySlicePtr := []string{}
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -76,6 +78,7 @@ func TestMarshal(t *testing.T) {
 		data: &Slice{
 			Strings:    []string{"1", "2", "", "3"},
 			StringsPtr: []*string{&stringPtr, &stringPtr},
+			SlicePtr:   &slicePtr,
 			Basics: []Basic{
 				{
 					String: "test",
@@ -94,6 +97,9 @@ func TestMarshal(t *testing.T) {
 			"strings.3=3",
 			"strings-ptr.0=test",
 			"strings-ptr.1=test",
+			"slice-ptr.0=0",
+			"slice-ptr.1=1",
+			"slice-ptr.2=2",
 			"basics.0.string=test",
 			"basics.0.int=42",
 			"basics.2.string=test",
@@ -104,11 +110,13 @@ func TestMarshal(t *testing.T) {
 	t.Run("empty-slice", run(TestCase{
 		data: &Slice{
 			Strings:    []string{},
+			SlicePtr:   &emptySlicePtr,
 			StringsPtr: []*string{},
 		},
 		expected: []string{
 			"strings=none",
 			"strings-ptr=none",
+			"slice-ptr=none",
 		},
 	}))
 
diff --git a/internal/args/unmarshal.go b/internal/args/unmarshal.go
index cbd7f3b3e9..7b906557b3 100644
--- a/internal/args/unmarshal.go
+++ b/internal/args/unmarshal.go
@@ -199,7 +199,7 @@ func set(dest reflect.Value, argNameWords []string, value string) error {
 	case reflect.Slice:
 		// If type is a slice:
 
-		// We handle special case where array=none creates an empty slice.
+		// When array=none we creates an empty slice.
 		if len(argNameWords) == 0 && value == emptySliceValue {
 			dest.Set(reflect.MakeSlice(dest.Type(), 0, 0))
 			return nil
@@ -210,7 +210,7 @@ func set(dest reflect.Value, argNameWords []string, value string) error {
 			return &MissingIndexOnArrayError{}
 		}
 
-		// We check if argNameWords[0] is an positive integer to handle cases like keys.0.value=12
+		// We check if argNameWords[0] is a positive integer to handle cases like keys.0.value=12
 		index, err := strconv.ParseUint(argNameWords[0], 10, 64)
 		if err != nil {
 			return &InvalidIndexError{Index: argNameWords[0]}
diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index 46a38b25b6..ab0950b620 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -17,6 +17,8 @@ func TestUnmarshalStruct(t *testing.T) {
 	}
 
 	stringPtr := "test"
+	slicePtr := []string{"0", "1", "2"}
+	emptySlicePtr := []string{}
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -164,6 +166,9 @@ func TestUnmarshalStruct(t *testing.T) {
 			"strings.3=test",
 			"strings-ptr.0=test",
 			"strings-ptr.1=test",
+			"slice-ptr.0=0",
+			"slice-ptr.1=1",
+			"slice-ptr.2=2",
 			"basics.0.string=test",
 			"basics.0.int=42",
 			"basics.1.string=test",
@@ -172,6 +177,7 @@ func TestUnmarshalStruct(t *testing.T) {
 		expected: &Slice{
 			Strings:    []string{"1", "2", "3", "test"},
 			StringsPtr: []*string{&stringPtr, &stringPtr},
+			SlicePtr:   &slicePtr,
 			Basics: []Basic{
 				{
 					String: "test",
@@ -188,10 +194,12 @@ func TestUnmarshalStruct(t *testing.T) {
 	t.Run("empty-slice", run(TestCase{
 		args: []string{
 			"strings=none",
+			"slice-ptr=none",
 			"strings-ptr=none",
 		},
 		expected: &Slice{
 			Strings:    []string{},
+			SlicePtr:   &emptySlicePtr,
 			StringsPtr: []*string{},
 		},
 	}))

From 274a651ae3c126cb4bb6e8294910ed87b218f0d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Thu, 13 Feb 2020 16:09:40 +0100
Subject: [PATCH 5/7] address comments

---
 internal/args/marshal.go        | 14 +++++++++-----
 internal/args/marshal_test.go   |  4 +---
 internal/args/unmarshal.go      | 15 +++++++++------
 internal/args/unmarshal_test.go | 22 +++++++++++-----------
 4 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/internal/args/marshal.go b/internal/args/marshal.go
index 4a3467be00..e70e460f53 100644
--- a/internal/args/marshal.go
+++ b/internal/args/marshal.go
@@ -118,17 +118,21 @@ func marshal(src reflect.Value, keys []string) (args []string, err error) {
 		if src.IsNil() {
 			return nil, nil
 		}
+
+		// When:
+		// - dest is a pointer to a slice
+		// - The slice is empty
+		// we return slice=none
+		if src.Elem().Kind() == reflect.Slice && src.Elem().Len() == 0 {
+			return append(args, marshalKeyValue(keys, emptySliceValue)), nil
+		}
+
 		// If type is a pointer we Marshal pointer.Elem()
 		return marshal(src.Elem(), keys)
 
 	case reflect.Slice:
 		// If type is a slice:
 
-		// If we explicitly try to marshal a non-nil empty slice we marshal it as args=none
-		if src.Len() == 0 && !src.IsNil() {
-			return append(args, marshalKeyValue(keys, emptySliceValue)), nil
-		}
-
 		// We loop through all items and marshal them with key = key.0, key.1, ....
 		args := []string(nil)
 		for i := 0; i < src.Len(); i++ {
diff --git a/internal/args/marshal_test.go b/internal/args/marshal_test.go
index b1cb5afa8e..3dd80779e4 100644
--- a/internal/args/marshal_test.go
+++ b/internal/args/marshal_test.go
@@ -16,7 +16,7 @@ func TestMarshal(t *testing.T) {
 
 	stringPtr := "test"
 	slicePtr := []string{"0", "1", "2"}
-	emptySlicePtr := []string{}
+	emptySlicePtr := []string(nil)
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -114,8 +114,6 @@ func TestMarshal(t *testing.T) {
 			StringsPtr: []*string{},
 		},
 		expected: []string{
-			"strings=none",
-			"strings-ptr=none",
 			"slice-ptr=none",
 		},
 	}))
diff --git a/internal/args/unmarshal.go b/internal/args/unmarshal.go
index 7b906557b3..a4ea6fd3fd 100644
--- a/internal/args/unmarshal.go
+++ b/internal/args/unmarshal.go
@@ -193,18 +193,21 @@ func set(dest reflect.Value, argNameWords []string, value string) error {
 			dest.Set(reflect.New(dest.Type().Elem()))
 		}
 
+		// When:
+		// - dest is a pointer to a slice
+		// - there is no more argNameWords left
+		// - value == none
+		// we let the slice empty and return
+		if dest.Elem().Kind() == reflect.Slice && len(argNameWords) == 0 && value == emptySliceValue {
+			return nil
+		}
+
 		// Call set with the pointer.Elem()
 		return set(dest.Elem(), argNameWords, value)
 
 	case reflect.Slice:
 		// If type is a slice:
 
-		// When array=none we creates an empty slice.
-		if len(argNameWords) == 0 && value == emptySliceValue {
-			dest.Set(reflect.MakeSlice(dest.Type(), 0, 0))
-			return nil
-		}
-
 		// We cannot handle slice without an index notation.
 		if len(argNameWords) == 0 {
 			return &MissingIndexOnArrayError{}
diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index ab0950b620..a0585749c1 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -18,7 +18,7 @@ func TestUnmarshalStruct(t *testing.T) {
 
 	stringPtr := "test"
 	slicePtr := []string{"0", "1", "2"}
-	emptySlicePtr := []string{}
+	emptySlicePtr := []string(nil)
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -193,32 +193,32 @@ func TestUnmarshalStruct(t *testing.T) {
 
 	t.Run("empty-slice", run(TestCase{
 		args: []string{
-			"strings=none",
+			//"strings=none",
 			"slice-ptr=none",
-			"strings-ptr=none",
+			//"strings-ptr=none",
 		},
 		expected: &Slice{
-			Strings:    []string{},
+			Strings:    []string(nil),
 			SlicePtr:   &emptySlicePtr,
-			StringsPtr: []*string{},
+			StringsPtr: []*string(nil),
 		},
 	}))
 
 	t.Run("simple-parent-child-conflict", run(TestCase{
 		args: []string{
-			"strings=none",
-			"strings.0=none",
+			"slice-ptr=none",
+			"slice-ptr.0=none",
 		},
-		error: "arguments 'strings' and 'strings.0' cannot be used simultaneously",
+		error: "arguments 'slice-ptr' and 'slice-ptr.0' cannot be used simultaneously",
 		data:  &Slice{},
 	}))
 
 	t.Run("simple-child-parent-conflict", run(TestCase{
 		args: []string{
-			"strings.0=none",
-			"strings=none",
+			"slice-ptr.0=none",
+			"slice-ptr=none",
 		},
-		error: "arguments 'strings.0' and 'strings' cannot be used simultaneously",
+		error: "arguments 'slice-ptr.0' and 'slice-ptr' cannot be used simultaneously",
 		data:  &Slice{},
 	}))
 

From b67553d7e19aecfd68f177efef32ea00a4208fbb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Thu, 13 Feb 2020 16:17:39 +0100
Subject: [PATCH 6/7] address comments

---
 internal/args/marshal_test.go   |  3 +--
 internal/args/unmarshal_test.go | 13 +++++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/internal/args/marshal_test.go b/internal/args/marshal_test.go
index 3dd80779e4..12c416983c 100644
--- a/internal/args/marshal_test.go
+++ b/internal/args/marshal_test.go
@@ -16,7 +16,6 @@ func TestMarshal(t *testing.T) {
 
 	stringPtr := "test"
 	slicePtr := []string{"0", "1", "2"}
-	emptySlicePtr := []string(nil)
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -110,7 +109,7 @@ func TestMarshal(t *testing.T) {
 	t.Run("empty-slice", run(TestCase{
 		data: &Slice{
 			Strings:    []string{},
-			SlicePtr:   &emptySlicePtr,
+			SlicePtr:   scw.StringsPtr(nil),
 			StringsPtr: []*string{},
 		},
 		expected: []string{
diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index a0585749c1..814c7d83bc 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -18,7 +18,6 @@ func TestUnmarshalStruct(t *testing.T) {
 
 	stringPtr := "test"
 	slicePtr := []string{"0", "1", "2"}
-	emptySlicePtr := []string(nil)
 
 	run := func(testCase TestCase) func(t *testing.T) {
 		return func(t *testing.T) {
@@ -193,17 +192,23 @@ func TestUnmarshalStruct(t *testing.T) {
 
 	t.Run("empty-slice", run(TestCase{
 		args: []string{
-			//"strings=none",
 			"slice-ptr=none",
-			//"strings-ptr=none",
 		},
 		expected: &Slice{
 			Strings:    []string(nil),
-			SlicePtr:   &emptySlicePtr,
+			SlicePtr:   scw.StringsPtr(nil),
 			StringsPtr: []*string(nil),
 		},
 	}))
 
+	t.Run("none-on-non-pointer-slice", run(TestCase{
+		args: []string{
+			"strings=none",
+		},
+		error: "cannot unmarshal arg 'strings=none': missing index on the array",
+		data:  &Slice{},
+	}))
+
 	t.Run("simple-parent-child-conflict", run(TestCase{
 		args: []string{
 			"slice-ptr=none",

From e63b9384ed50d6e727c317eac5485cc50533c553 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Qu=C3=A9r=C3=A9?= <jquere@scaleway.com>
Date: Thu, 13 Feb 2020 16:25:41 +0100
Subject: [PATCH 7/7] fix

---
 internal/args/unmarshal_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/internal/args/unmarshal_test.go b/internal/args/unmarshal_test.go
index 814c7d83bc..3a4d1a45b4 100644
--- a/internal/args/unmarshal_test.go
+++ b/internal/args/unmarshal_test.go
@@ -419,7 +419,6 @@ func TestUnmarshalStruct(t *testing.T) {
 			},
 		},
 	}))
-}
 
 	t.Run("common-prefix-args", run(TestCase{
 		args: []string{