Merge lp:~niemeyer/pyjuju/go-initial-formula-meta into lp:pyjuju/go

[Gustavo Niemeyer]

Initial (and incomplete) metadata.yaml parsing.

Stacks on the unmerged go-iface-schema branch.

[William Reade (fwereade)]

[0]

+ "peers": schema.Map(schema.String(), ifaceExpander(1)),

Is this right? It matches the Python, but the docs seem to suggest it should be ifaceExpander(nil):

http://bazaar.launchpad.net/~ensemble/ensemble/trunk/view/head:/docs/source/formula.rst#L69

Otherwise, +1.

review: Approve

[Kapil Thangavelu (hazmat)]

Looks good.

[0] it definitely make sense for the default limit on a peer rel to be one. the docs should be updated.

review: Approve

=== modified file 'formula/formula.go'
--- formula/formula.go	2011-08-27 14:47:24 +0000
+++ formula/formula.go	2011-08-27 14:47:24 +0000
@@ -2,7 +2,9 @@
 
 import (
 	"fmt"
+	"io/ioutil"
 	"launchpad.net/ensemble/go/schema"
+	"launchpad.net/goyaml"
 	"os"
 	"strconv"
 	"strings"
@@ -32,11 +34,48 @@
 	return
 }
 
-var ifaceSchema = schema.FieldMap(schema.Fields{
-	"interface": schema.String(),
-	"limit":     schema.OneOf(schema.Const(nil), schema.Int()),
-	"optional":  schema.Bool(),
-}, nil)
+type Meta struct {
+	Name        string
+	Revision    int
+	Summary     string
+	Description string
+}
+
+// ReadMeta reads a metadata.yaml file and returns its representation.
+func ReadMeta(path string) (meta *Meta, err os.Error) {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return
+	}
+	meta, err = ParseMeta(data)
+	if err != nil {
+		err = os.NewError(fmt.Sprintf("%s: %s", path, err))
+	}
+	return
+}
+
+// ParseMeta parses the data of a metadata.yaml file and returns
+// its representation.
+func ParseMeta(data []byte) (meta *Meta, err os.Error) {
+	raw := make(map[interface{}]interface{})
+	err = goyaml.Unmarshal(data, raw)
+	if err != nil {
+		return
+	}
+	v, err := formulaSchema.Coerce(raw, nil)
+	if err != nil {
+		return
+	}
+	m := v.(schema.M)
+	meta = &Meta{}
+	meta.Name = m["name"].(string)
+	// Schema decodes as int64, but the int range should be good
+	// enough for revisions.
+	meta.Revision = int(m["revision"].(int64))
+	meta.Summary = m["summary"].(string)
+	meta.Description = m["description"].(string)
+	return
+}
 
 // Schema coercer that expands the interface shorthand notation.
 // A consistent format is easier to work with than considering the
@@ -99,3 +138,23 @@
 	}
 	return ifaceSchema.Coerce(m, path)
 }
+
+var ifaceSchema = schema.FieldMap(schema.Fields{
+	"interface": schema.String(),
+	"limit":     schema.OneOf(schema.Const(nil), schema.Int()),
+	"optional":  schema.Bool(),
+}, nil)
+
+var formulaSchema = schema.FieldMap(
+	schema.Fields{
+		"ensemble":    schema.Const("formula"),
+		"name":        schema.String(),
+		"revision":    schema.Int(),
+		"summary":     schema.String(),
+		"description": schema.String(),
+		"peers":       schema.Map(schema.String(), ifaceExpander(1)),
+		"provides":    schema.Map(schema.String(), ifaceExpander(nil)),
+		"requires":    schema.Map(schema.String(), ifaceExpander(1)),
+	},
+	schema.Optional{"provides", "requires", "peers"},
+)

=== modified file 'formula/formula_test.go'
--- formula/formula_test.go	2011-08-27 14:47:24 +0000
+++ formula/formula_test.go	2011-08-27 14:47:24 +0000
@@ -1,10 +1,13 @@
 package formula_test
 
 import (
+	"io/ioutil"
 	"testing"
 	. "launchpad.net/gocheck"
 	"launchpad.net/ensemble/go/formula"
 	"launchpad.net/ensemble/go/schema"
+	"launchpad.net/goyaml"
+	"path/filepath"
 )
 
 func Test(t *testing.T) {
@@ -35,6 +38,57 @@
 	c.Assert(err, Matches, `Missing formula revision: "local:foo-x"`)
 }
 
+const dummyMeta = "testrepo/dummy/metadata.yaml"
+
+func (s *S) TestReadMeta(c *C) {
+	meta, err := formula.ReadMeta(dummyMeta)
+	c.Assert(err, IsNil)
+	c.Assert(meta.Name, Equals, "dummy")
+	c.Assert(meta.Revision, Equals, 1)
+	c.Assert(meta.Summary, Equals, "That's a dummy formula.")
+	c.Assert(meta.Description, Equals,
+		"This is a longer description which\npotentially contains multiple lines.\n")
+}
+
+func (s *S) TestParseMeta(c *C) {
+	data, err := ioutil.ReadFile(dummyMeta)
+	c.Assert(err, IsNil)
+
+	meta, err := formula.ParseMeta(data)
+	c.Assert(err, IsNil)
+	c.Assert(meta.Name, Equals, "dummy")
+	c.Assert(meta.Revision, Equals, 1)
+	c.Assert(meta.Summary, Equals, "That's a dummy formula.")
+	c.Assert(meta.Description, Equals,
+		"This is a longer description which\npotentially contains multiple lines.\n")
+}
+
+func (s *S) TestMetaHeader(c *C) {
+	yaml := ReadYaml(dummyMeta)
+	yaml["ensemble"] = "foo"
+	data := DumpYaml(yaml)
+
+	_, err := formula.ParseMeta(data)
+	c.Assert(err, Matches, `ensemble: expected "formula", got "foo"`)
+}
+
+func (s *S) TestMetaErrorWithPath(c *C) {
+	yaml := ReadYaml(dummyMeta)
+	yaml["ensemble"] = "foo"
+	data := DumpYaml(yaml)
+
+	path := filepath.Join(c.MkDir(), "mymeta.yaml")
+
+	_, err := formula.ReadMeta(path)
+	c.Assert(err, Matches, `.*/.*/mymeta\.yaml.*no such file.*`)
+
+	err = ioutil.WriteFile(path, data, 0644)
+	c.Assert(err, IsNil)
+
+	_, err = formula.ReadMeta(path)
+	c.Assert(err, Matches, `/.*/mymeta\.yaml: ensemble: expected "formula", got "foo"`)
+}
+
 // Test rewriting of a given interface specification into long form.
 //
 // InterfaceExpander uses `coerce` to do one of two things:
@@ -84,3 +138,25 @@
 	c.Assert(err, IsNil)
 	c.Assert(v, Equals, schema.M{"interface": "http", "limit": int64(1), "optional": false})
 }
+
+
+func ReadYaml(path string) map[interface{}]interface{} {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		panic(err)
+	}
+	m := make(map[interface{}]interface{})
+	err = goyaml.Unmarshal(data, m)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+func DumpYaml(v interface{}) []byte {
+	data, err := goyaml.Marshal(v)
+	if err != nil {
+		panic(err)
+	}
+	return data
+}