Basic manifest implementation (#4)

* Basic first pass at JSON-based manifest

* Add rudimentary ReadManifest() tests

* Implement gps.RootManifest methods on Manifest

* Add copyright headers

* Fatalf on test that invalidates later checks

* Rewrite TestDependencyConstraints comment as TODO

* Consolidate types package back into main

manifest.go

@@ -0,0 +1,117 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/sdboyer/gps"
+)
+
+type Manifest struct {
+	Dependencies gps.ProjectConstraints
+	Ovr          gps.ProjectConstraints
+	Ignores      []string
+}
+
+type rawManifest struct {
+	Dependencies map[string]possibleProps `json:"dependencies"`
+	Overrides    map[string]possibleProps `json:"overrides"`
+	Ignores      []string                 `json:"ignores"`
+}
+
+type possibleProps struct {
+	Branch      string `json:"branch"`
+	Revision    string `json:"revision"`
+	Version     string `json:"version"`
+	NetworkName string `json:"network_name"`
+}
+
+func ReadManifest(r io.Reader) (*Manifest, error) {
+	rm := rawManifest{}
+	err := json.NewDecoder(r).Decode(&rm)
+	if err != nil {
+		return nil, err
+	}
+
+	m := &Manifest{
+		Dependencies: make(gps.ProjectConstraints, len(rm.Dependencies)),
+		Ovr:          make(gps.ProjectConstraints, len(rm.Overrides)),
+		Ignores:      rm.Ignores,
+	}
+
+	for n, pp := range rm.Dependencies {
+		m.Dependencies[gps.ProjectRoot(n)], err = toProps(n, pp)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	for n, pp := range rm.Overrides {
+		m.Ovr[gps.ProjectRoot(n)], err = toProps(n, pp)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return m, nil
+}
+
+func toProps(n string, p possibleProps) (pp gps.ProjectProperties, err error) {
+	if p.Branch != "" {
+		if p.Version != "" || p.Revision != "" {
+			return pp, fmt.Errorf("multiple constraints specified for %s, can only specify one", n)
+		}
+		pp.Constraint = gps.NewBranch(p.Branch)
+	} else if p.Version != "" {
+		if p.Revision != "" {
+			return pp, fmt.Errorf("multiple constraints specified for %s, can only specify one", n)
+		}
+
+		// always semver if we can
+		pp.Constraint, err = gps.NewSemverConstraint(p.Version)
+		if err != nil {
+			// but if not, fall back on plain versions
+			pp.Constraint = gps.NewVersion(p.Version)
+		}
+	} else if p.Revision != "" {
+		pp.Constraint = gps.Revision(p.Revision)
+	} else {
+		// If the user specifies nothing, it means an open constraint (accept
+		// anything).
+		pp.Constraint = gps.Any()
+	}
+
+	pp.NetworkName = p.NetworkName
+	return pp, nil
+}
+
+func (m *Manifest) DependencyConstraints() gps.ProjectConstraints {
+	return m.Dependencies
+}
+
+func (m *Manifest) TestDependencyConstraints() gps.ProjectConstraints {
+	// TODO decide whether we're going to incorporate this or not
+	return nil
+}
+
+func (m *Manifest) Overrides() gps.ProjectConstraints {
+	return m.Ovr
+}
+
+func (m *Manifest) IgnorePackages() map[string]bool {
+	if len(m.Ignores) == 0 {
+		return nil
+	}
+
+	mp := make(map[string]bool, len(m.Ignores))
+	for _, i := range m.Ignores {
+		mp[i] = true
+	}
+
+	return mp
+}

manifest_test.go

@@ -0,0 +1,98 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/sdboyer/gps"
+)
+
+func TestReadManifest(t *testing.T) {
+	const je = `{
+    "dependencies": {
+        "github.com/sdboyer/gps": {
+            "branch": "master",
+            "revision": "d05d5aca9f895d19e9265839bffeadd74a2d2ecb",
+            "version": "^v0.12.0",
+            "network_name": "https://github.com/sdboyer/gps"
+        }
+    },
+    "overrides": {
+        "github.com/sdboyer/gps": {
+            "branch": "master",
+            "revision": "d05d5aca9f895d19e9265839bffeadd74a2d2ecb",
+            "version": "^v0.12.0",
+            "network_name": "https://github.com/sdboyer/gps"
+        }
+    },
+    "ignores": [
+        "github.com/foo/bar"
+    ]
+}`
+
+	const jg = `{
+    "dependencies": {
+        "github.com/sdboyer/gps": {
+            "version": "^v0.12.0"
+        },
+        "github.com/babble/brook": {
+            "revision": "d05d5aca9f895d19e9265839bffeadd74a2d2ecb"
+        }
+    },
+    "overrides": {
+        "github.com/sdboyer/gps": {
+            "branch": "master",
+            "network_name": "https://github.com/sdboyer/gps"
+        }
+    },
+    "ignores": [
+        "github.com/foo/bar"
+    ]
+}`
+
+	_, err := ReadManifest(strings.NewReader(je))
+	if err == nil {
+		t.Error("Reading manifest with invalid props should have caused error, but did not")
+	} else if !strings.Contains(err.Error(), "multiple constraints") {
+		t.Errorf("Unexpected error %q; expected multiple constraint error", err)
+	}
+
+	m2, err := ReadManifest(strings.NewReader(jg))
+	if err != nil {
+		t.Fatalf("Should have read Manifest correctly, but got err %q", err)
+	}
+
+	c, _ := gps.NewSemverConstraint("^v0.12.0")
+	em := Manifest{
+		Dependencies: map[gps.ProjectRoot]gps.ProjectProperties{
+			gps.ProjectRoot("github.com/sdboyer/gps"): {
+				Constraint: c,
+			},
+			gps.ProjectRoot("github.com/babble/brook"): {
+				Constraint: gps.Revision("d05d5aca9f895d19e9265839bffeadd74a2d2ecb"),
+			},
+		},
+		Ovr: map[gps.ProjectRoot]gps.ProjectProperties{
+			gps.ProjectRoot("github.com/sdboyer/gps"): {
+				NetworkName: "https://github.com/sdboyer/gps",
+				Constraint:  gps.NewBranch("master"),
+			},
+		},
+		Ignores: []string{"github.com/foo/bar"},
+	}
+
+	if !reflect.DeepEqual(m2.Dependencies, em.Dependencies) {
+		t.Error("Valid manifest's dependencies did not parse as expected")
+	}
+	if !reflect.DeepEqual(m2.Ovr, em.Ovr) {
+		t.Error("Valid manifest's overrides did not parse as expected")
+	}
+	if !reflect.DeepEqual(m2.Ignores, em.Ignores) {
+		t.Error("Valid manifest's ignores did not parse as expected")
+	}
+}