patch/remove: add remove sub-cmd

Implement the :patch remove command. Remove a patch set from the
respository and from the internal storage. Note that in git, this will
change all commit hashes that appear after the removed one since the
commit hash depends on its parents. Adjust the code to handle such cases
and add tests for this.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

3 files changed, 345 insertions, 0 deletions

diff --git a/lib/pama/pama_test.go b/lib/pama/pama_test.go
new file mode 100644
index 00000000..7a4d1961
--- /dev/null
+++ b/lib/pama/pama_test.go
@@ -0,0 +1,166 @@
+package pama_test
+
+import (
+	"errors"
+
+	"git.sr.ht/~rjarry/aerc/lib/pama"
+	"git.sr.ht/~rjarry/aerc/lib/pama/models"
+)
+
+var errNotFound = errors.New("not found")
+
+func newCommit(id, subj, tag string) models.Commit {
+	return models.Commit{ID: id, Subject: subj, Tag: tag}
+}
+
+func newTestManager(
+	commits []string,
+	subjects []string,
+	data map[string]models.Project,
+	current string,
+) (pama.PatchManager, models.RevisionController, models.PersistentStorer) {
+	rc := mockRevctrl{
+		commitIDs: commits,
+		titles:    subjects,
+	}
+	store := mockStore{
+		data:    data,
+		current: current,
+	}
+	return pama.FromFunc(
+		nil,
+		func(_ string, _ string) (models.RevisionController, error) {
+			return &rc, nil
+		},
+		func() models.PersistentStorer {
+			return &store
+		},
+	), &rc, &store
+}
+
+type mockRevctrl struct {
+	commitIDs []string
+	titles    []string
+}
+
+func (c *mockRevctrl) Support() bool {
+	return true
+}
+
+func (c *mockRevctrl) Clean() bool {
+	return true
+}
+
+func (c *mockRevctrl) Root() (string, error) {
+	return "", nil
+}
+
+func (c *mockRevctrl) Head() (string, error) {
+	return c.commitIDs[len(c.commitIDs)-1], nil
+}
+
+func (c *mockRevctrl) History(commit string) ([]string, error) {
+	for i, s := range c.commitIDs {
+		if s == commit {
+			cp := make([]string, len(c.commitIDs[i+1:]))
+			copy(cp, c.commitIDs[i+1:])
+			return cp, nil
+		}
+	}
+	return nil, errNotFound
+}
+
+func (c *mockRevctrl) Exists(commit string) bool {
+	for _, s := range c.commitIDs {
+		if s == commit {
+			return true
+		}
+	}
+	return false
+}
+
+func (c *mockRevctrl) Subject(commit string) string {
+	for i, s := range c.commitIDs {
+		if s == commit {
+			return c.titles[i]
+		}
+	}
+	return ""
+}
+
+func (c *mockRevctrl) Author(commit string) string {
+	return ""
+}
+
+func (c *mockRevctrl) Date(commit string) string {
+	return ""
+}
+
+func (c *mockRevctrl) Remove(commit string) error {
+	for i, s := range c.commitIDs {
+		if s == commit {
+			c.commitIDs = append(c.commitIDs[:i], c.commitIDs[i+1:]...)
+			c.titles = append(c.titles[:i], c.titles[i+1:]...)
+			// modify commitIDs to simulate a "real" change in
+			// commit history that will also change all subsequent
+			// commitIDs
+			for j := i; j < len(c.commitIDs); j++ {
+				c.commitIDs[j] += "_new"
+			}
+			return nil
+		}
+	}
+	return errNotFound
+}
+
+func (c *mockRevctrl) ApplyCmd() string {
+	return ""
+}
+
+type mockStore struct {
+	data    map[string]models.Project
+	current string
+}
+
+func (s *mockStore) StoreProject(p models.Project, ow bool) error {
+	_, ok := s.data[p.Name]
+	if ok && !ow {
+		return errors.New("alreay there")
+	}
+	s.data[p.Name] = p
+	return nil
+}
+
+func (s *mockStore) DeleteProject(name string) error {
+	delete(s.data, name)
+	return nil
+}
+
+func (s *mockStore) CurrentName() (string, error) {
+	return s.current, nil
+}
+
+func (s *mockStore) SetCurrent(c string) error {
+	s.current = c
+	return nil
+}
+
+func (s *mockStore) Current() (models.Project, error) {
+	return s.data[s.current], nil
+}
+
+func (s *mockStore) Names() ([]string, error) {
+	var names []string
+	for name := range s.data {
+		names = append(names, name)
+	}
+	return names, nil
+}
+
+func (s *mockStore) Projects() ([]models.Project, error) {
+	var ps []models.Project
+	for _, p := range s.data {
+		ps = append(ps, p)
+	}
+	return ps, nil
+}
diff --git a/lib/pama/remove.go b/lib/pama/remove.go
new file mode 100644
index 00000000..d74874a1
--- /dev/null
+++ b/lib/pama/remove.go
@@ -0,0 +1,94 @@
+package pama
+
+import (
+	"fmt"
+
+	"git.sr.ht/~rjarry/aerc/lib/pama/models"
+	"git.sr.ht/~rjarry/aerc/log"
+)
+
+func (m PatchManager) RemovePatch(patch string) error {
+	p, err := m.CurrentProject()
+	if err != nil {
+		return err
+	}
+
+	if !models.Commits(p.Commits).HasTag(patch) {
+		return fmt.Errorf("Patch '%s' not found in project '%s'", patch, p.Name)
+	}
+
+	rc, err := m.rc(p.RevctrlID, p.Root)
+	if err != nil {
+		return revErr(err)
+	}
+
+	if !rc.Clean() {
+		return fmt.Errorf("Aborting... There are unstaged changes " +
+			"or a rebase in progress")
+	}
+
+	toRemove := make([]models.Commit, 0)
+	for _, c := range p.Commits {
+		if !rc.Exists(c.ID) {
+			log.Errorf("failed to find commit. %v", c)
+			return fmt.Errorf("Cannot remove patch. " +
+				"Please rebase first with ':patch rebase'")
+		}
+		if c.Tag == patch {
+			toRemove = append(toRemove, c)
+		}
+	}
+
+	removed := make(map[string]struct{})
+	for i := len(toRemove) - 1; i >= 0; i-- {
+		commitID := toRemove[i].ID
+		beforeIDs, err := rc.History(commitID)
+		if err != nil {
+			log.Errorf("failed to remove %v (commits before): %v", toRemove[i], err)
+			continue
+		}
+		err = rc.Remove(commitID)
+		if err != nil {
+			log.Errorf("failed to remove %v (remove): %v", toRemove[i], err)
+			continue
+		}
+		removed[commitID] = struct{}{}
+		afterIDs, err := rc.History(p.Base.ID)
+		if err != nil {
+			log.Errorf("failed to remove %v (commits after): %v", toRemove[i], err)
+			continue
+		}
+		afterIDs = afterIDs[len(afterIDs)-len(beforeIDs):]
+		transform := make(map[string]string)
+		for j := 0; j < len(beforeIDs); j++ {
+			transform[beforeIDs[j]] = afterIDs[j]
+		}
+		for j, c := range p.Commits {
+			if newId, ok := transform[c.ID]; ok {
+				msgid := p.Commits[j].MessageId
+				p.Commits[j] = models.NewCommit(
+					rc,
+					newId,
+					p.Commits[j].Tag,
+				)
+				p.Commits[j].MessageId = msgid
+			}
+		}
+	}
+
+	if len(removed) < len(toRemove) {
+		return fmt.Errorf("Failed to remove commits. Removed %d of %d.",
+			len(removed), len(toRemove))
+	}
+
+	commits := make([]models.Commit, 0, len(p.Commits))
+	for _, c := range p.Commits {
+		if _, ok := removed[c.ID]; ok {
+			continue
+		}
+		commits = append(commits, c)
+	}
+	p.Commits = commits
+
+	return storeErr(m.store().StoreProject(p, true))
+}
diff --git a/lib/pama/remove_test.go b/lib/pama/remove_test.go
new file mode 100644
index 00000000..c9ce6c65
--- /dev/null
+++ b/lib/pama/remove_test.go
@@ -0,0 +1,85 @@
+package pama_test
+
+import (
+	"reflect"
+	"testing"
+
+	"git.sr.ht/~rjarry/aerc/lib/pama"
+	"git.sr.ht/~rjarry/aerc/lib/pama/models"
+)
+
+func TestPatchmgmt_Remove(t *testing.T) {
+	setup := func(p models.Project) (pama.PatchManager, models.RevisionController, models.PersistentStorer) {
+		return newTestManager(
+			[]string{"0", "1", "2", "3", "4", "5"},
+			[]string{"0", "a", "b", "c", "d", "f"},
+			map[string]models.Project{p.Name: p}, p.Name,
+		)
+	}
+
+	tests := []struct {
+		name    string
+		remove  string
+		commits []models.Commit
+		want    []models.Commit
+	}{
+		{
+			name:   "remove only patch",
+			remove: "patch1",
+			commits: []models.Commit{
+				newCommit("1", "a", "patch1"),
+			},
+			want: []models.Commit{},
+		},
+		{
+			name:   "remove second one of two patch",
+			remove: "patch2",
+			commits: []models.Commit{
+				newCommit("1", "a", "patch1"),
+				newCommit("2", "b", "patch2"),
+			},
+			want: []models.Commit{
+				newCommit("1", "a", "patch1"),
+			},
+		},
+		{
+			name:   "remove first one of two patch",
+			remove: "patch1",
+			commits: []models.Commit{
+				newCommit("1", "a", "patch1"),
+				newCommit("2", "b", "patch2"),
+			},
+			want: []models.Commit{
+				newCommit("2_new", "b", "patch2"),
+			},
+		},
+	}
+
+	for _, test := range tests {
+		p := models.Project{
+			Name:    "project1",
+			Commits: test.commits,
+			Base:    newCommit("0", "0", ""),
+		}
+		mgr, rc, _ := setup(p)
+
+		err := mgr.RemovePatch(test.remove)
+		if err != nil {
+			t.Errorf("test '%s' failed. %v", test.name, err)
+		}
+
+		q, _ := mgr.CurrentProject()
+		if !reflect.DeepEqual(q.Commits, test.want) {
+			t.Errorf("test '%s' failed. Commits don't match: "+
+				"got %v, but wanted %v", test.name, q.Commits,
+				test.want)
+		}
+
+		if len(test.want) > 0 {
+			last := test.want[len(test.want)-1]
+			if !rc.Exists(last.ID) {
+				t.Errorf("test '%s' failed. Could not find last commits: %v", test.name, last)
+			}
+		}
+	}
+}