Reviewers: mp+221156_code.launchpad.net,

Message:
Please take a look.

Description:
Allow charms without a peer listed.



https://code.launchpad.net/~jimmiebtlr/juju-core/fix-no-peers-charms/+merge/221156

(do not edit description out of merge proposal)


Please review this at https://codereview.appspot.com/101810046/

Affected files (+61, -24 lines):
   A [revision details]
   M charm/meta.go
   M charm/meta_test.go
   M schema/schema.go
   M schema/schema_test.go
   A testing/repo/quantal/empty-fields/metadata.yaml


Index: [revision details]
=== added file '[revision details]'
--- [revision details]	2012-01-01 00:00:00 +0000
+++ [revision details]	2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision: tarmac-20140528050243-agcci9rl0vqrr911
+New revision: <email address hidden>

Index: charm/meta.go
=== modified file 'charm/meta.go'
--- charm/meta.go	2014-04-09 16:36:12 +0000
+++ charm/meta.go	2014-05-21 01:59:05 +0000
@@ -96,13 +96,13 @@
  	Summary     string
  	Description string
  	Subordinate bool
-	Provides    map[string]Relation `bson:",omitempty"`
-	Requires    map[string]Relation `bson:",omitempty"`
-	Peers       map[string]Relation `bson:",omitempty"`
-	Format      int                 `bson:",omitempty"`
-	OldRevision int                 `bson:",omitempty"` // Obsolete
-	Categories  []string            `bson:",omitempty"`
-	Series      string              `bson:",omitempty"`
+	Provides    map[string]Relation
+	Requires    map[string]Relation
+	Peers       map[string]Relation
+	Format      int      `bson:",omitempty"`
+	OldRevision int      `bson:",omitempty"` // Obsolete
+	Categories  []string `bson:",omitempty"`
+	Series      string   `bson:",omitempty"`
  }

  func generateRelationHooks(relName string, allHooks map[string]bool) {
@@ -262,10 +262,10 @@
  }

  func parseRelations(relations interface{}, role RelationRole)  
map[string]Relation {
+	result := make(map[string]Relation)
  	if relations == nil {
-		return nil
+		return result
  	}
-	result := make(map[string]Relation)
  	for name, rel := range relations.(map[string]interface{}) {
  		relMap := rel.(map[string]interface{})
  		relation := Relation{


Index: charm/meta_test.go
=== modified file 'charm/meta_test.go'
--- charm/meta_test.go	2014-04-09 16:36:12 +0000
+++ charm/meta_test.go	2014-05-28 05:01:55 +0000
@@ -93,8 +93,8 @@
  		Interface: "mysql",
  		Scope:     charm.ScopeGlobal,
  	})
-	c.Assert(meta.Requires, gc.IsNil)
-	c.Assert(meta.Peers, gc.IsNil)
+	c.Assert(meta.Requires, gc.DeepEquals, map[string]charm.Relation{})
+	c.Assert(meta.Peers, gc.DeepEquals, map[string]charm.Relation{})

  	meta, err = charm.ReadMeta(repoMeta("riak"))
  	c.Assert(err, gc.IsNil)
@@ -117,7 +117,7 @@
  		Limit:     1,
  		Scope:     charm.ScopeGlobal,
  	})
-	c.Assert(meta.Requires, gc.IsNil)
+	c.Assert(meta.Requires, gc.DeepEquals, map[string]charm.Relation{})

  	meta, err = charm.ReadMeta(repoMeta("terracotta"))
  	c.Assert(err, gc.IsNil)
@@ -135,7 +135,7 @@
  		Limit:     1,
  		Scope:     charm.ScopeGlobal,
  	})
-	c.Assert(meta.Requires, gc.IsNil)
+	c.Assert(meta.Requires, gc.DeepEquals, map[string]charm.Relation{})

  	meta, err = charm.ReadMeta(repoMeta("wordpress"))
  	c.Assert(err, gc.IsNil)
@@ -160,7 +160,13 @@
  		Optional:  true,
  		Scope:     charm.ScopeGlobal,
  	})
-	c.Assert(meta.Peers, gc.IsNil)
+	c.Assert(meta.Peers, gc.DeepEquals, map[string]charm.Relation{})
+
+	meta, err = charm.ReadMeta(repoMeta("empty-fields"))
+	c.Assert(err, gc.IsNil)
+	c.Assert(meta.Provides, gc.DeepEquals, map[string]charm.Relation{})
+	c.Assert(meta.Requires, gc.DeepEquals, map[string]charm.Relation{})
+	c.Assert(meta.Peers, gc.DeepEquals, map[string]charm.Relation{})
  }

  var relationsConstraintsTests = []struct {
@@ -396,12 +402,15 @@
  	for i, codec := range codecs {
  		c.Logf("codec %d", i)
  		empty_input := charm.Meta{}
+		empty_input.Provides = make(map[string]charm.Relation)
+		empty_input.Peers = make(map[string]charm.Relation)
+		empty_input.Requires = make(map[string]charm.Relation)
  		data, err := codec.Marshal(empty_input)
  		c.Assert(err, gc.IsNil)
  		var empty_output charm.Meta
  		err = codec.Unmarshal(data, &empty_output)
  		c.Assert(err, gc.IsNil)
-		c.Assert(empty_input, gc.DeepEquals, empty_output)
+		c.Assert(empty_output, gc.DeepEquals, empty_input)
  	}
  }



Index: schema/schema.go
=== modified file 'schema/schema.go'
--- schema/schema.go	2014-01-15 10:50:11 +0000
+++ schema/schema.go	2014-05-21 01:38:00 +0000
@@ -293,6 +293,11 @@

  func (c mapC) Coerce(v interface{}, path []string) (interface{}, error) {
  	rv := reflect.ValueOf(v)
+
+	// treat nil value as empty map
+	if rv.Kind() == reflect.Invalid {
+		return make(map[interface{}]interface{}), nil
+	}
  	if rv.Kind() != reflect.Map {
  		return nil, error_{"map", v, path}
  	}
@@ -334,6 +339,11 @@

  func (c stringMapC) Coerce(v interface{}, path []string) (interface{},  
error) {
  	rv := reflect.ValueOf(v)
+
+	// treat nil value as empty map
+	if rv.Kind() == reflect.Invalid {
+		return make(map[string]interface{}), nil
+	}
  	if rv.Kind() != reflect.Map {
  		return nil, error_{"map", v, path}
  	}
@@ -399,6 +409,11 @@

  func (c fieldMapC) Coerce(v interface{}, path []string) (interface{},  
error) {
  	rv := reflect.ValueOf(v)
+
+	// treat nil value as empty map
+	if rv.Kind() == reflect.Invalid {
+		return make(map[string]interface{}), nil
+	}
  	if rv.Kind() != reflect.Map {
  		return nil, error_{"map", v, path}
  	}
@@ -488,6 +503,11 @@

  func (c mapSetC) Coerce(v interface{}, path []string) (interface{}, error)  
{
  	rv := reflect.ValueOf(v)
+
+	// treat nil value as empty map
+	if rv.Kind() == reflect.Invalid {
+		return make(map[string]interface{}), nil
+	}
  	if rv.Kind() != reflect.Map {
  		return nil, error_{"map", v, path}
  	}


Index: schema/schema_test.go
=== modified file 'schema/schema_test.go'
--- schema/schema_test.go	2014-01-14 13:10:26 +0000
+++ schema/schema_test.go	2014-05-28 04:58:04 +0000
@@ -250,8 +250,8 @@
  	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got int\\(42\\)")

  	out, err = sch.Coerce(nil, aPath)
-	c.Assert(out, gc.IsNil)
-	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got nothing")
+	c.Assert(err, gc.IsNil)
+	c.Assert(out, gc.DeepEquals, map[interface{}]interface{}{})

  	out, err = sch.Coerce(map[int]int{1: 1}, aPath)
  	c.Assert(out, gc.IsNil)
@@ -274,12 +274,12 @@
  	c.Assert(out, gc.DeepEquals, map[string]interface{}{"a": int64(1), "b":  
int64(2)})

  	out, err = sch.Coerce(42, aPath)
-	c.Assert(out, gc.IsNil)
  	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got int\\(42\\)")
+	c.Assert(out, gc.IsNil)

  	out, err = sch.Coerce(nil, aPath)
-	c.Assert(out, gc.IsNil)
-	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got nothing")
+	c.Assert(err, gc.IsNil)
+	c.Assert(out, gc.DeepEquals, map[string]interface{}{})

  	out, err = sch.Coerce(map[int]int{1: 1}, aPath)
  	c.Assert(out, gc.IsNil)
@@ -306,8 +306,8 @@
  	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got int\\(42\\)")

  	out, err = sch.Coerce(nil, aPath)
-	c.Assert(out, gc.IsNil)
-	c.Assert(err, gc.ErrorMatches, "<path>: expected map, got nothing")
+	c.Assert(err, gc.IsNil)
+	c.Assert(out, gc.DeepEquals, map[string]interface{}{})

  	out, err = sch.Coerce(map[string]interface{}{"a": "A", "b": "C"}, aPath)
  	c.Assert(out, gc.IsNil)
@@ -416,8 +416,8 @@
  	c.Assert(err, gc.ErrorMatches, `<path>: expected map, got int\(42\)`)

  	out, err = sch.Coerce(nil, aPath)
-	c.Assert(out, gc.IsNil)
-	c.Assert(err, gc.ErrorMatches, `<path>: expected map, got nothing`)
+	c.Assert(err, gc.IsNil)
+	c.Assert(out, gc.DeepEquals, map[string]interface{}{})

  	// First path entry shouldn't have dots in an error message.
  	out, err = sch.Coerce(map[string]int{"a": 1}, nil)


Index: testing/repo/quantal/empty-fields/metadata.yaml
=== added file 'testing/repo/quantal/empty-fields/metadata.yaml'
--- testing/repo/quantal/empty-fields/metadata.yaml	1970-01-01 00:00:00  
+0000
+++ testing/repo/quantal/empty-fields/metadata.yaml	2014-05-03 17:48:01  
+0000
@@ -0,0 +1,6 @@
+name: empty-fields
+summary: "Kerosene powered blender"
+description: "Description here"
+provides:
+peers:
+requires: