added linker for atlasssian stash

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support Before sha for Bitbucket, from [@jkdev81](https://github.com/jkdev81).
 - Support for creating GitHub deployment hooks, from [@bradrydzewski](https://github.com/bradrydzewski).
 - Endpoint to get organization membership for GitHub, from [@bradrydzewski](https://github.com/bradrydzewski).
+- Functions to generate deep links to git resources, from [@bradrydzewski](https://github.com/bradrydzewski).
 
 ### Fixed
 - Fix issue getting a GitLab commit by ref, from [@bradrydzewski](https://github.com/bradrydzewski).

scm/driver/stash/linker.go

@@ -0,0 +1,45 @@
+// Copyright 2017 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package stash
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/drone/go-scm/scm"
+)
+
+type linker struct {
+	base string
+}
+
+// Resource returns a link to the resource.
+func (l *linker) Resource(ctx context.Context, repo string, ref scm.Reference) (string, error) {
+	namespace, name := scm.Split(repo)
+	switch {
+	case scm.IsTag(ref.Path):
+		return fmt.Sprintf("%sprojects/%s/repos/%s/browse?at=%s", l.base, namespace, name, ref.Path), nil
+	case scm.IsPullRequest(ref.Path):
+		d := scm.ExtractPullRequest(ref.Path)
+		return fmt.Sprintf("%sprojects/%s/repos/%s/pull-requests/%d/overview", l.base, namespace, name, d), nil
+	default:
+		return fmt.Sprintf("%sprojects/%s/repos/%s/commits/%s", l.base, namespace, name, ref.Sha), nil
+	}
+}
+
+// Diff returns a link to the diff.
+func (l *linker) Diff(ctx context.Context, repo string, source, target scm.Reference) (string, error) {
+	namespace, name := scm.Split(repo)
+	if scm.IsPullRequest(target.Path) {
+		d := scm.ExtractPullRequest(target.Path)
+		return fmt.Sprintf("%sprojects/%s/repos/%s/pull-requests/%d/diff", l.base, namespace, name, d), nil
+	}
+	if target.Path != "" && source.Path != "" {
+		return fmt.Sprintf("%sprojects/%s/repos/%s/compare/diff?sourceBranch=%s&targetBranch=%s", l.base, namespace, name, source.Path, target.Path), nil
+	}
+	// TODO(bradrydzewski) bitbucket server does not appear to have
+	// an endpoint for evaluating diffs of two commits.
+	return "", scm.ErrNotSupported
+}

scm/driver/stash/linker_test.go

@@ -0,0 +1,91 @@
+// Copyright 2017 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package stash
+
+import (
+	"context"
+	"testing"
+
+	"github.com/drone/go-scm/scm"
+)
+
+func TestLink(t *testing.T) {
+	tests := []struct {
+		path string
+		sha  string
+		want string
+	}{
+		{
+			path: "refs/heads/master",
+			sha:  "a7389057b0eb027e73b32a81e3c5923a71d01dde",
+			want: "https://stash.acme.com/projects/PRJ/repos/hello-world/commits/a7389057b0eb027e73b32a81e3c5923a71d01dde",
+		},
+		{
+			path: "refs/pull/42/head",
+			sha:  "a7389057b0eb027e73b32a81e3c5923a71d01dde",
+			want: "https://stash.acme.com/projects/PRJ/repos/hello-world/pull-requests/42/overview",
+		},
+		{
+			path: "refs/tags/v1.0.0",
+			want: "https://stash.acme.com/projects/PRJ/repos/hello-world/browse?at=refs/tags/v1.0.0",
+		},
+	}
+
+	for _, test := range tests {
+		client, _ := New("https://stash.acme.com")
+		ref := scm.Reference{
+			Path: test.path,
+			Sha:  test.sha,
+		}
+		got, err := client.Linker.Resource(context.Background(), "PRJ/hello-world", ref)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		want := test.want
+		if got != want {
+			t.Errorf("Want link %q, got %q", want, got)
+		}
+	}
+}
+
+func TestDiff(t *testing.T) {
+	tests := []struct {
+		source scm.Reference
+		target scm.Reference
+		want   string
+	}{
+		{
+			source: scm.Reference{Path: "refs/heads/master"},
+			target: scm.Reference{Path: "refs/heads/develop"},
+			want:   "https://stash.acme.com/projects/PRJ/repos/hello-world/compare/diff?sourceBranch=refs/heads/master&targetBranch=refs/heads/develop",
+		},
+		{
+			target: scm.Reference{Path: "refs/pull/12/head"},
+			want:   "https://stash.acme.com/projects/PRJ/repos/hello-world/pull-requests/12/diff",
+		},
+	}
+
+	for _, test := range tests {
+		client, _ := New("https://stash.acme.com")
+		got, err := client.Linker.Diff(context.Background(), "PRJ/hello-world", test.source, test.target)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		want := test.want
+		if got != want {
+			t.Errorf("Want link %q, got %q", want, got)
+		}
+	}
+
+	source := scm.Reference{}
+	target := scm.Reference{}
+	client, _ := New("https://stash.acme.com")
+	_, err := client.Linker.Diff(context.Background(), "PRJ/hello-world", source, target)
+	if err != scm.ErrNotSupported {
+		t.Errorf("Expect ErrNotSupported when refpath is empty")
+	}
+}

scm/driver/stash/stash.go

@@ -33,6 +33,7 @@ func New(uri string) (*scm.Client, error) {
 	client.BaseURL = base
 	// initialize services
 	client.Driver = scm.DriverStash
+	client.Linker = &linker{base.String()}
 	client.Contents = &contentService{client}
 	client.Git = &gitService{client}
 	client.Issues = &issueService{client}