Cleanup various small issues with post package

6 files changed, 603 insertions, 673 deletions

diff --git a/srv/src/post/date.go b/srv/src/post/date.go
deleted file mode 100644
index 34fe109..0000000
--- a/srv/src/post/date.go
+++ /dev/null
@@ -1,59 +0,0 @@
-package post
-
-import (
-	"database/sql/driver"
-	"fmt"
-	"time"
-)
-
-// Date represents a calendar date with no timezone information attached.
-type Date struct {
-	Year  int
-	Month time.Month
-	Day   int
-}
-
-// DateFromTime converts a Time into a Date, truncating all non-date
-// information.
-func DateFromTime(t time.Time) Date {
-	t = t.UTC()
-	return Date{
-		Year:  t.Year(),
-		Month: t.Month(),
-		Day:   t.Day(),
-	}
-}
-
-// ToTime converts a Date into a Time. The returned time will be UTC midnight of
-// the Date.
-func (d *Date) ToTime() time.Time {
-	return time.Date(d.Year, d.Month, d.Day, 0, 0, 0, 0, time.UTC)
-}
-
-// Scan implements the sql.Scanner interface.
-func (d *Date) Scan(src interface{}) error {
-
-	if src == nil {
-		*d = Date{}
-		return nil
-	}
-
-	ts, ok := src.(int64)
-
-	if !ok {
-		return fmt.Errorf("cannot scan value %#v into Date", src)
-	}
-
-	*d = DateFromTime(time.Unix(ts, 0))
-	return nil
-}
-
-// Value implements the driver.Valuer interface.
-func (d Date) Value() (driver.Value, error) {
-
-	if d == (Date{}) {
-		return nil, nil
-	}
-
-	return d.ToTime().Unix(), nil
-}
diff --git a/srv/src/post/post.go b/srv/src/post/post.go
index 7803c82..bdc48af 100644
--- a/srv/src/post/post.go
+++ b/srv/src/post/post.go
@@ -1,9 +1,20 @@
-// Package post deals with the storage and rending of blog post.
+// Package post deals with the storage and rendering of blog posts.
 package post
 
 import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"path"
 	"regexp"
 	"strings"
+	"time"
+)
+
+var (
+	// ErrPostNotFound is used to indicate a Post could not be found in the
+	// Store.
+	ErrPostNotFound = errors.New("post not found")
 )
 
 var titleCleanRegexp = regexp.MustCompile(`[^a-z ]`)
@@ -25,3 +36,342 @@ type Post struct {
 	Series      string
 	Body        string
 }
+
+// StoredPost is a Post which has been stored in a Store, and has been given
+// some extra fields as a result.
+type StoredPost struct {
+	Post
+
+	PublishedAt   time.Time
+	LastUpdatedAt time.Time
+}
+
+// URL returns the relative URL of the StoredPost.
+func (p StoredPost) URL() string {
+	return path.Join(
+		fmt.Sprintf(
+			"%d/%0d/%0d",
+			p.PublishedAt.Year(),
+			p.PublishedAt.Month(),
+			p.PublishedAt.Day(),
+		),
+		p.ID+".html",
+	)
+}
+
+// Store is used for storing posts to a persistent storage.
+type Store interface {
+
+	// Set sets the Post data into the storage, keyed by the Post's ID. It
+	// overwrites a previous Post with the same ID, if there was one.
+	Set(post Post, now time.Time) error
+
+	// Get returns count StoredPosts, sorted time descending, offset by the given page
+	// number. The returned boolean indicates if there are more pages or not.
+	Get(page, count int) ([]StoredPost, bool, error)
+
+	// GetByID will return the StoredPost with the given ID, or ErrPostNotFound.
+	GetByID(id string) (StoredPost, error)
+
+	// GetBySeries returns all StoredPosts with the given series, sorted time
+	// ascending, or empty slice.
+	GetBySeries(series string) ([]StoredPost, error)
+
+	// GetByTag returns all StoredPosts with the given tag, sorted time
+	// ascending, or empty slice.
+	GetByTag(tag string) ([]StoredPost, error)
+
+	// Delete will delete the StoredPost with the given ID.
+	Delete(id string) error
+}
+
+type store struct {
+	db *sql.DB
+}
+
+// NewStore initializes a new Store using an existing SQLDB.
+func NewStore(db *SQLDB) Store {
+	return &store{
+		db: db.db,
+	}
+}
+
+// if the callback returns an error then the transaction is aborted.
+func (s *store) withTx(cb func(*sql.Tx) error) error {
+
+	tx, err := s.db.Begin()
+
+	if err != nil {
+		return fmt.Errorf("starting transaction: %w", err)
+	}
+
+	if err := cb(tx); err != nil {
+
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			return fmt.Errorf(
+				"rolling back transaction: %w (original error: %v)",
+				rollbackErr, err,
+			)
+		}
+
+		return fmt.Errorf("performing transaction: %w (rolled back)", err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("committing transaction: %w", err)
+	}
+
+	return nil
+}
+
+func (s *store) Set(post Post, now time.Time) error {
+	return s.withTx(func(tx *sql.Tx) error {
+
+		nowTS := now.Unix()
+
+		nowSQL := sql.NullInt64{Int64: nowTS, Valid: !now.IsZero()}
+
+		_, err := tx.Exec(
+			`INSERT INTO posts (
+				id, title, description, series, published_at, body
+			)
+			VALUES
+			(?, ?, ?, ?, ?, ?)
+			ON CONFLICT (id) DO UPDATE SET
+				title=excluded.title,
+				description=excluded.description,
+				series=excluded.series,
+				last_updated_at=?,
+				body=excluded.body`,
+			post.ID,
+			post.Title,
+			post.Description,
+			&sql.NullString{String: post.Series, Valid: post.Series != ""},
+			nowSQL,
+			post.Body,
+			nowSQL,
+		)
+
+		if err != nil {
+			return fmt.Errorf("inserting into posts: %w", err)
+		}
+
+		// this is a bit of a hack, but it allows us to update the tagset without
+		// doing a diff.
+		_, err = tx.Exec(`DELETE FROM post_tags WHERE post_id = ?`, post.ID)
+
+		if err != nil {
+			return fmt.Errorf("clearning post tags: %w", err)
+		}
+
+		for _, tag := range post.Tags {
+
+			_, err = tx.Exec(
+				`INSERT INTO post_tags (post_id, tag) VALUES (?, ?)
+			ON CONFLICT DO NOTHING`,
+				post.ID,
+				tag,
+			)
+
+			if err != nil {
+				return fmt.Errorf("inserting tag %q: %w", tag, err)
+			}
+		}
+
+		return nil
+	})
+}
+
+func (s *store) get(
+	querier interface {
+		Query(string, ...interface{}) (*sql.Rows, error)
+	},
+	limit, offset int,
+	where string, whereArgs ...interface{},
+) (
+	[]StoredPost, error,
+) {
+
+	query := `
+		SELECT
+			p.id, p.title, p.description, p.series, pt.tag,
+			p.published_at, p.last_updated_at,
+			p.body
+		FROM posts p
+		LEFT JOIN post_tags pt ON (p.id = pt.post_id)
+		` + where + `
+		ORDER BY p.published_at ASC, p.title ASC`
+
+	if limit > 0 {
+		query += fmt.Sprintf(" LIMIT %d", limit)
+	}
+
+	if offset > 0 {
+		query += fmt.Sprintf(" OFFSET %d", offset)
+	}
+
+	rows, err := querier.Query(query, whereArgs...)
+
+	if err != nil {
+		return nil, fmt.Errorf("selecting: %w", err)
+	}
+
+	var posts []StoredPost
+
+	for rows.Next() {
+
+		var (
+			post                       StoredPost
+			series, tag                sql.NullString
+			publishedAt, lastUpdatedAt sql.NullInt64
+		)
+
+		err := rows.Scan(
+			&post.ID, &post.Title, &post.Description, &series, &tag,
+			&publishedAt, &lastUpdatedAt,
+			&post.Body,
+		)
+
+		if err != nil {
+			return nil, fmt.Errorf("scanning row: %w", err)
+		}
+
+		if tag.Valid {
+
+			if l := len(posts); l > 0 && posts[l-1].ID == post.ID {
+				posts[l-1].Tags = append(posts[l-1].Tags, tag.String)
+				continue
+			}
+
+			post.Tags = append(post.Tags, tag.String)
+		}
+
+		post.Series = series.String
+
+		if publishedAt.Valid {
+			post.PublishedAt = time.Unix(publishedAt.Int64, 0).UTC()
+		}
+
+		if lastUpdatedAt.Valid {
+			post.LastUpdatedAt = time.Unix(lastUpdatedAt.Int64, 0).UTC()
+		}
+
+		posts = append(posts, post)
+	}
+
+	if err := rows.Close(); err != nil {
+		return nil, fmt.Errorf("closing row iterator: %w", err)
+	}
+
+	return posts, nil
+}
+
+func (s *store) Get(page, count int) ([]StoredPost, bool, error) {
+
+	posts, err := s.get(s.db, count+1, page*count, ``)
+
+	if err != nil {
+		return nil, false, fmt.Errorf("querying posts: %w", err)
+	}
+
+	var hasMore bool
+
+	if len(posts) > count {
+		hasMore = true
+		posts = posts[:count]
+	}
+
+	return posts, hasMore, nil
+}
+
+func (s *store) GetByID(id string) (StoredPost, error) {
+
+	posts, err := s.get(s.db, 0, 0, `WHERE p.id=?`, id)
+
+	if err != nil {
+		return StoredPost{}, fmt.Errorf("querying posts: %w", err)
+	}
+
+	if len(posts) == 0 {
+		return StoredPost{}, ErrPostNotFound
+	}
+
+	if len(posts) > 1 {
+		panic(fmt.Sprintf("got back multiple posts querying id %q: %+v", id, posts))
+	}
+
+	return posts[0], nil
+}
+
+func (s *store) GetBySeries(series string) ([]StoredPost, error) {
+	return s.get(s.db, 0, 0, `WHERE p.series=?`, series)
+}
+
+func (s *store) GetByTag(tag string) ([]StoredPost, error) {
+
+	var posts []StoredPost
+
+	err := s.withTx(func(tx *sql.Tx) error {
+
+		rows, err := tx.Query(`SELECT post_id FROM post_tags WHERE tag = ?`, tag)
+
+		if err != nil {
+			return fmt.Errorf("querying post_tags by tag: %w", err)
+		}
+
+		var (
+			placeholders []string
+			whereArgs    []interface{}
+		)
+
+		for rows.Next() {
+
+			var id string
+
+			if err := rows.Scan(&id); err != nil {
+				rows.Close()
+				return fmt.Errorf("scanning id: %w", err)
+			}
+
+			whereArgs = append(whereArgs, id)
+			placeholders = append(placeholders, "?")
+		}
+
+		if err := rows.Close(); err != nil {
+			return fmt.Errorf("closing row iterator: %w", err)
+		}
+
+		where := fmt.Sprintf("WHERE p.id IN (%s)", strings.Join(placeholders, ","))
+
+		if posts, err = s.get(tx, 0, 0, where, whereArgs...); err != nil {
+			return fmt.Errorf("querying for ids %+v: %w", whereArgs, err)
+		}
+
+		return nil
+	})
+
+	return posts, err
+}
+
+func (s *store) Delete(id string) error {
+
+	tx, err := s.db.Begin()
+
+	if err != nil {
+		return fmt.Errorf("starting transaction: %w", err)
+	}
+
+	if _, err := tx.Exec(`DELETE FROM post_tags WHERE post_id = ?`, id); err != nil {
+		return fmt.Errorf("deleting from post_tags: %w", err)
+	}
+
+	if _, err := tx.Exec(`DELETE FROM posts WHERE id = ?`, id); err != nil {
+		return fmt.Errorf("deleting from posts: %w", err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("committing transaction: %w", err)
+	}
+
+	return nil
+}
diff --git a/srv/src/post/post_test.go b/srv/src/post/post_test.go
index 47c9ae8..55a29ea 100644
--- a/srv/src/post/post_test.go
+++ b/srv/src/post/post_test.go
@@ -1,10 +1,13 @@
 package post
 
 import (
+	"sort"
 	"strconv"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/tilinna/clock"
 )
 
 func TestNewID(t *testing.T) {
@@ -30,3 +33,224 @@ func TestNewID(t *testing.T) {
 		})
 	}
 }
+
+func testPost(i int) Post {
+	istr := strconv.Itoa(i)
+	return Post{
+		ID:          istr,
+		Title:       istr,
+		Description: istr,
+		Body:        istr,
+	}
+}
+
+type storeTestHarness struct {
+	clock *clock.Mock
+	store Store
+}
+
+func newStoreTestHarness(t *testing.T) storeTestHarness {
+
+	clock := clock.NewMock(time.Now().UTC().Truncate(1 * time.Hour))
+
+	db := NewInMemSQLDB()
+	t.Cleanup(func() { db.Close() })
+
+	store := NewStore(db)
+
+	return storeTestHarness{
+		clock: clock,
+		store: store,
+	}
+}
+
+func (h *storeTestHarness) testStoredPost(i int) StoredPost {
+	post := testPost(i)
+	return StoredPost{
+		Post:        post,
+		PublishedAt: h.clock.Now(),
+	}
+}
+
+func TestStore(t *testing.T) {
+
+	assertPostEqual := func(t *testing.T, exp, got StoredPost) {
+		t.Helper()
+		sort.Strings(exp.Tags)
+		sort.Strings(got.Tags)
+		assert.Equal(t, exp, got)
+	}
+
+	assertPostsEqual := func(t *testing.T, exp, got []StoredPost) {
+		t.Helper()
+
+		if !assert.Len(t, got, len(exp), "exp:%+v\ngot: %+v", exp, got) {
+			return
+		}
+
+		for i := range exp {
+			assertPostEqual(t, exp[i], got[i])
+		}
+	}
+
+	t.Run("not_found", func(t *testing.T) {
+		h := newStoreTestHarness(t)
+
+		_, err := h.store.GetByID("foo")
+		assert.ErrorIs(t, err, ErrPostNotFound)
+	})
+
+	t.Run("set_get_delete", func(t *testing.T) {
+		h := newStoreTestHarness(t)
+
+		now := h.clock.Now().UTC()
+
+		post := testPost(0)
+		post.Tags = []string{"foo", "bar"}
+
+		assert.NoError(t, h.store.Set(post, now))
+
+		gotPost, err := h.store.GetByID(post.ID)
+		assert.NoError(t, err)
+
+		assertPostEqual(t, StoredPost{
+			Post:        post,
+			PublishedAt: now,
+		}, gotPost)
+
+		// we will now try updating the post on a different day, and ensure it
+		// updates properly
+
+		h.clock.Add(24 * time.Hour)
+		newNow := h.clock.Now().UTC()
+
+		post.Title = "something else"
+		post.Series = "whatever"
+		post.Body = "anything"
+		post.Tags = []string{"bar", "baz"}
+
+		assert.NoError(t, h.store.Set(post, newNow))
+
+		gotPost, err = h.store.GetByID(post.ID)
+		assert.NoError(t, err)
+
+		assertPostEqual(t, StoredPost{
+			Post:          post,
+			PublishedAt:   now,
+			LastUpdatedAt: newNow,
+		}, gotPost)
+
+		// delete the post, it should go away
+		assert.NoError(t, h.store.Delete(post.ID))
+
+		_, err = h.store.GetByID(post.ID)
+		assert.ErrorIs(t, err, ErrPostNotFound)
+	})
+
+	t.Run("get", func(t *testing.T) {
+		h := newStoreTestHarness(t)
+
+		now := h.clock.Now().UTC()
+
+		posts := []StoredPost{
+			h.testStoredPost(0),
+			h.testStoredPost(1),
+			h.testStoredPost(2),
+			h.testStoredPost(3),
+		}
+
+		for _, post := range posts {
+			assert.NoError(t, h.store.Set(post.Post, now))
+		}
+
+		gotPosts, hasMore, err := h.store.Get(0, 2)
+		assert.NoError(t, err)
+		assert.True(t, hasMore)
+		assertPostsEqual(t, posts[:2], gotPosts)
+
+		gotPosts, hasMore, err = h.store.Get(1, 2)
+		assert.NoError(t, err)
+		assert.False(t, hasMore)
+		assertPostsEqual(t, posts[2:4], gotPosts)
+
+		posts = append(posts, h.testStoredPost(4))
+		assert.NoError(t, h.store.Set(posts[4].Post, now))
+
+		gotPosts, hasMore, err = h.store.Get(1, 2)
+		assert.NoError(t, err)
+		assert.True(t, hasMore)
+		assertPostsEqual(t, posts[2:4], gotPosts)
+
+		gotPosts, hasMore, err = h.store.Get(2, 2)
+		assert.NoError(t, err)
+		assert.False(t, hasMore)
+		assertPostsEqual(t, posts[4:], gotPosts)
+	})
+
+	t.Run("get_by_series", func(t *testing.T) {
+		h := newStoreTestHarness(t)
+
+		now := h.clock.Now().UTC()
+
+		posts := []StoredPost{
+			h.testStoredPost(0),
+			h.testStoredPost(1),
+			h.testStoredPost(2),
+			h.testStoredPost(3),
+		}
+
+		posts[0].Series = "foo"
+		posts[1].Series = "bar"
+		posts[2].Series = "bar"
+
+		for _, post := range posts {
+			assert.NoError(t, h.store.Set(post.Post, now))
+		}
+
+		fooPosts, err := h.store.GetBySeries("foo")
+		assert.NoError(t, err)
+		assertPostsEqual(t, posts[:1], fooPosts)
+
+		barPosts, err := h.store.GetBySeries("bar")
+		assert.NoError(t, err)
+		assertPostsEqual(t, posts[1:3], barPosts)
+
+		bazPosts, err := h.store.GetBySeries("baz")
+		assert.NoError(t, err)
+		assert.Empty(t, bazPosts)
+	})
+
+	t.Run("get_by_tag", func(t *testing.T) {
+
+		h := newStoreTestHarness(t)
+
+		now := h.clock.Now().UTC()
+
+		posts := []StoredPost{
+			h.testStoredPost(0),
+			h.testStoredPost(1),
+			h.testStoredPost(2),
+			h.testStoredPost(3),
+		}
+
+		posts[0].Tags = []string{"foo"}
+		posts[1].Tags = []string{"foo", "bar"}
+		posts[2].Tags = []string{"bar"}
+
+		for _, post := range posts {
+			assert.NoError(t, h.store.Set(post.Post, now))
+		}
+
+		fooPosts, err := h.store.GetByTag("foo")
+		assert.NoError(t, err)
+		assertPostsEqual(t, posts[:2], fooPosts)
+
+		barPosts, err := h.store.GetByTag("bar")
+		assert.NoError(t, err)
+		assertPostsEqual(t, posts[1:3], barPosts)
+
+		bazPosts, err := h.store.GetByTag("baz")
+		assert.NoError(t, err)
+		assert.Empty(t, bazPosts)
+	})
+}
diff --git a/srv/src/post/sql.go b/srv/src/post/sql.go
index fb9468f..16cdc95 100644
--- a/srv/src/post/sql.go
+++ b/srv/src/post/sql.go
@@ -7,10 +7,12 @@ import (
 
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	migrate "github.com/rubenv/sql-migrate"
+
+	_ "github.com/mattn/go-sqlite3" // we need dis
 )
 
-var migrations = []*migrate.Migration{
-	&migrate.Migration{
+var migrations = &migrate.MemoryMigrationSource{Migrations: []*migrate.Migration{
+	{
 		Id: "1",
 		Up: []string{
 			`CREATE TABLE posts (
@@ -24,18 +26,25 @@ var migrations = []*migrate.Migration{
 
 				body TEXT NOT NULL
 			)`,
+
 			`CREATE TABLE post_tags (
 				post_id TEXT NOT NULL,
 				tag     TEXT NOT NULL,
 				UNIQUE(post_id, tag)
 			)`,
+
+			`CREATE TABLE assets (
+				id   TEXT NOT NULL PRIMARY KEY,
+				body BLOB NOT NULL
+			)`,
 		},
 		Down: []string{
+			"DROP TABLE assets",
 			"DROP TABLE post_tags",
 			"DROP TABLE posts",
 		},
 	},
-}
+}}
 
 // SQLDB is a sqlite3 database which can be used by storage interfaces within
 // this package.
@@ -43,7 +52,7 @@ type SQLDB struct {
 	db *sql.DB
 }
 
-// NewSQLDB initializes and returns a new sqlite3 database for post storage
+// NewSQLDB initializes and returns a new sqlite3 database for storage
 // intefaces. The db will  be created within the given data directory.
 func NewSQLDB(dataDir cfg.DataDir) (*SQLDB, error) {
 
@@ -54,8 +63,6 @@ func NewSQLDB(dataDir cfg.DataDir) (*SQLDB, error) {
 		return nil, fmt.Errorf("opening sqlite file at %q: %w", path, err)
 	}
 
-	migrations := &migrate.MemoryMigrationSource{Migrations: migrations}
-
 	if _, err := migrate.Exec(db, "sqlite3", migrations, migrate.Up); err != nil {
 		return nil, fmt.Errorf("running migrations: %w", err)
 	}
@@ -63,6 +70,21 @@ func NewSQLDB(dataDir cfg.DataDir) (*SQLDB, error) {
 	return &SQLDB{db}, nil
 }
 
+// NewSQLDB is like NewSQLDB, but the database will be initialized in memory.
+func NewInMemSQLDB() *SQLDB {
+
+	db, err := sql.Open("sqlite3", ":memory:")
+	if err != nil {
+		panic(fmt.Errorf("opening sqlite in memory: %w", err))
+	}
+
+	if _, err := migrate.Exec(db, "sqlite3", migrations, migrate.Up); err != nil {
+		panic(fmt.Errorf("running migrations: %w", err))
+	}
+
+	return &SQLDB{db}
+}
+
 // Close cleans up loose resources being held by the db.
 func (db *SQLDB) Close() error {
 	return db.db.Close()
diff --git a/srv/src/post/store.go b/srv/src/post/store.go
deleted file mode 100644
index 5da17a9..0000000
--- a/srv/src/post/store.go
+++ /dev/null
@@ -1,362 +0,0 @@
-package post
-
-import (
-	"database/sql"
-	"errors"
-	"fmt"
-	"path"
-	"strings"
-	"time"
-
-	_ "github.com/mattn/go-sqlite3" // we need dis
-)
-
-var (
-	// ErrNotFound is used to indicate a Post could not be found in the
-	// database.
-	ErrNotFound = errors.New("not found")
-)
-
-// StoredPost is a Post which has been stored in a Store, and has been given
-// some extra fields as a result.
-type StoredPost struct {
-	Post
-
-	PublishedAt   time.Time
-	LastUpdatedAt time.Time
-}
-
-// URL returns the relative URL of the StoredPost.
-func (p StoredPost) URL() string {
-	return path.Join(
-		fmt.Sprintf(
-			"%d/%0d/%0d",
-			p.PublishedAt.Year(),
-			p.PublishedAt.Month(),
-			p.PublishedAt.Day(),
-		),
-		p.ID+".html",
-	)
-}
-
-// Store is used for storing posts to a persistent storage.
-type Store interface {
-
-	// Set sets the Post data into the storage, keyed by the Post's ID. It
-	// overwrites a previous Post with the same ID, if there was one.
-	Set(post Post, now time.Time) error
-
-	// Get returns count StoredPosts, sorted time descending, offset by the given page
-	// number. The returned boolean indicates if there are more pages or not.
-	Get(page, count int) ([]StoredPost, bool, error)
-
-	// GetByID will return the StoredPost with the given ID, or ErrNotFound.
-	GetByID(id string) (StoredPost, error)
-
-	// GetBySeries returns all StoredPosts with the given series, sorted time
-	// ascending, or empty slice.
-	GetBySeries(series string) ([]StoredPost, error)
-
-	// GetByTag returns all StoredPosts with the given tag, sorted time
-	// ascending, or empty slice.
-	GetByTag(tag string) ([]StoredPost, error)
-
-	// Delete will delete the StoredPost with the given ID.
-	Delete(id string) error
-
-	Close() error
-}
-
-type store struct {
-	db *sql.DB
-}
-
-// NewStore initializes a new Store using an existing SQLDB.
-func NewStore(db *SQLDB) Store {
-	return &store{
-		db: db.db,
-	}
-}
-
-func (s *store) Close() error {
-	return s.db.Close()
-}
-
-// if the callback returns an error then the transaction is aborted.
-func (s *store) withTx(cb func(*sql.Tx) error) error {
-
-	tx, err := s.db.Begin()
-
-	if err != nil {
-		return fmt.Errorf("starting transaction: %w", err)
-	}
-
-	if err := cb(tx); err != nil {
-
-		if rollbackErr := tx.Rollback(); rollbackErr != nil {
-			return fmt.Errorf(
-				"rolling back transaction: %w (original error: %v)",
-				rollbackErr, err,
-			)
-		}
-
-		return fmt.Errorf("performing transaction: %w (rolled back)", err)
-	}
-
-	if err := tx.Commit(); err != nil {
-		return fmt.Errorf("committing transaction: %w", err)
-	}
-
-	return nil
-}
-
-func (s *store) Set(post Post, now time.Time) error {
-	return s.withTx(func(tx *sql.Tx) error {
-
-		nowTS := now.Unix()
-
-		nowSQL := sql.NullInt64{Int64: nowTS, Valid: !now.IsZero()}
-
-		_, err := tx.Exec(
-			`INSERT INTO posts (
-			id, title, description, series, published_at, body
-		)
-		VALUES
-		(?, ?, ?, ?, ?, ?)
-		ON CONFLICT (id) DO UPDATE SET
-			title=excluded.title,
-			description=excluded.description,
-			series=excluded.series,
-			last_updated_at=?,
-			body=excluded.body`,
-			post.ID,
-			post.Title,
-			post.Description,
-			&sql.NullString{String: post.Series, Valid: post.Series != ""},
-			nowSQL,
-			post.Body,
-			nowSQL,
-		)
-
-		if err != nil {
-			return fmt.Errorf("inserting into posts: %w", err)
-		}
-
-		// this is a bit of a hack, but it allows us to update the tagset without
-		// doing a diff.
-		_, err = tx.Exec(`DELETE FROM post_tags WHERE post_id = ?`, post.ID)
-
-		if err != nil {
-			return fmt.Errorf("clearning post tags: %w", err)
-		}
-
-		for _, tag := range post.Tags {
-
-			_, err = tx.Exec(
-				`INSERT INTO post_tags (post_id, tag) VALUES (?, ?)
-			ON CONFLICT DO NOTHING`,
-				post.ID,
-				tag,
-			)
-
-			if err != nil {
-				return fmt.Errorf("inserting tag %q: %w", tag, err)
-			}
-		}
-
-		return nil
-	})
-}
-
-func (s *store) get(
-	querier interface {
-		Query(string, ...interface{}) (*sql.Rows, error)
-	},
-	limit, offset int,
-	where string, whereArgs ...interface{},
-) (
-	[]StoredPost, error,
-) {
-
-	query := `SELECT
-		p.id, p.title, p.description, p.series, pt.tag,
-		p.published_at, p.last_updated_at,
-		p.body
-	FROM posts p
-	LEFT JOIN post_tags pt ON (p.id = pt.post_id)
-	` + where + `
-	ORDER BY p.published_at ASC, p.title ASC`
-
-	if limit > 0 {
-		query += fmt.Sprintf(" LIMIT %d", limit)
-	}
-
-	if offset > 0 {
-		query += fmt.Sprintf(" OFFSET %d", offset)
-	}
-
-	rows, err := querier.Query(query, whereArgs...)
-
-	if err != nil {
-		return nil, fmt.Errorf("selecting: %w", err)
-	}
-
-	var posts []StoredPost
-
-	for rows.Next() {
-
-		var (
-			post                       StoredPost
-			series, tag                sql.NullString
-			publishedAt, lastUpdatedAt sql.NullInt64
-		)
-
-		err := rows.Scan(
-			&post.ID, &post.Title, &post.Description, &series, &tag,
-			&publishedAt, &lastUpdatedAt,
-			&post.Body,
-		)
-
-		if err != nil {
-			return nil, fmt.Errorf("scanning row: %w", err)
-		}
-
-		if tag.Valid {
-
-			if l := len(posts); l > 0 && posts[l-1].ID == post.ID {
-				posts[l-1].Tags = append(posts[l-1].Tags, tag.String)
-				continue
-			}
-
-			post.Tags = append(post.Tags, tag.String)
-		}
-
-		post.Series = series.String
-
-		if publishedAt.Valid {
-			post.PublishedAt = time.Unix(publishedAt.Int64, 0).UTC()
-		}
-
-		if lastUpdatedAt.Valid {
-			post.LastUpdatedAt = time.Unix(lastUpdatedAt.Int64, 0).UTC()
-		}
-
-		posts = append(posts, post)
-	}
-
-	if err := rows.Close(); err != nil {
-		return nil, fmt.Errorf("closing row iterator: %w", err)
-	}
-
-	return posts, nil
-}
-
-func (s *store) Get(page, count int) ([]StoredPost, bool, error) {
-
-	posts, err := s.get(s.db, count+1, page*count, ``)
-
-	if err != nil {
-		return nil, false, fmt.Errorf("querying posts: %w", err)
-	}
-
-	var hasMore bool
-
-	if len(posts) > count {
-		hasMore = true
-		posts = posts[:count]
-	}
-
-	return posts, hasMore, nil
-}
-
-func (s *store) GetByID(id string) (StoredPost, error) {
-
-	posts, err := s.get(s.db, 0, 0, `WHERE p.id=?`, id)
-
-	if err != nil {
-		return StoredPost{}, fmt.Errorf("querying posts: %w", err)
-	}
-
-	if len(posts) == 0 {
-		return StoredPost{}, ErrNotFound
-	}
-
-	if len(posts) > 1 {
-		panic(fmt.Sprintf("got back multiple posts querying id %q: %+v", id, posts))
-	}
-
-	return posts[0], nil
-}
-
-func (s *store) GetBySeries(series string) ([]StoredPost, error) {
-	return s.get(s.db, 0, 0, `WHERE p.series=?`, series)
-}
-
-func (s *store) GetByTag(tag string) ([]StoredPost, error) {
-
-	var posts []StoredPost
-
-	err := s.withTx(func(tx *sql.Tx) error {
-
-		rows, err := tx.Query(`SELECT post_id FROM post_tags WHERE tag = ?`, tag)
-
-		if err != nil {
-			return fmt.Errorf("querying post_tags by tag: %w", err)
-		}
-
-		var (
-			placeholders []string
-			whereArgs    []interface{}
-		)
-
-		for rows.Next() {
-
-			var id string
-
-			if err := rows.Scan(&id); err != nil {
-				rows.Close()
-				return fmt.Errorf("scanning id: %w", err)
-			}
-
-			whereArgs = append(whereArgs, id)
-			placeholders = append(placeholders, "?")
-		}
-
-		if err := rows.Close(); err != nil {
-			return fmt.Errorf("closing row iterator: %w", err)
-		}
-
-		where := fmt.Sprintf("WHERE p.id IN (%s)", strings.Join(placeholders, ","))
-
-		if posts, err = s.get(tx, 0, 0, where, whereArgs...); err != nil {
-			return fmt.Errorf("querying for ids %+v: %w", whereArgs, err)
-		}
-
-		return nil
-	})
-
-	return posts, err
-}
-
-func (s *store) Delete(id string) error {
-
-	tx, err := s.db.Begin()
-
-	if err != nil {
-		return fmt.Errorf("starting transaction: %w", err)
-	}
-
-	if _, err := tx.Exec(`DELETE FROM post_tags WHERE post_id = ?`, id); err != nil {
-		return fmt.Errorf("deleting from post_tags: %w", err)
-	}
-
-	if _, err := tx.Exec(`DELETE FROM posts WHERE id = ?`, id); err != nil {
-		return fmt.Errorf("deleting from posts: %w", err)
-	}
-
-	if err := tx.Commit(); err != nil {
-		return fmt.Errorf("committing transaction: %w", err)
-	}
-
-	return nil
-}
diff --git a/srv/src/post/store_test.go b/srv/src/post/store_test.go
deleted file mode 100644
index 3ccf5d7..0000000
--- a/srv/src/post/store_test.go
+++ /dev/null
@@ -1,245 +0,0 @@
-package post
-
-import (
-	"sort"
-	"strconv"
-	"testing"
-	"time"
-
-	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
-	"github.com/stretchr/testify/assert"
-	"github.com/tilinna/clock"
-)
-
-func testPost(i int) Post {
-	istr := strconv.Itoa(i)
-	return Post{
-		ID:          istr,
-		Title:       istr,
-		Description: istr,
-		Body:        istr,
-	}
-}
-
-type storeTestHarness struct {
-	clock *clock.Mock
-	store Store
-}
-
-func newStoreTestHarness(t *testing.T) storeTestHarness {
-
-	var dataDir cfg.DataDir
-
-	if err := dataDir.Init(); err != nil {
-		t.Fatal(err)
-	}
-
-	t.Cleanup(func() { dataDir.Close() })
-
-	clock := clock.NewMock(time.Now().UTC().Truncate(1 * time.Hour))
-
-	db, err := NewSQLDB(dataDir)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Cleanup(func() { db.Close() })
-
-	store := NewStore(db)
-
-	return storeTestHarness{
-		clock: clock,
-		store: store,
-	}
-}
-
-func (h *storeTestHarness) testStoredPost(i int) StoredPost {
-	post := testPost(i)
-	return StoredPost{
-		Post:        post,
-		PublishedAt: h.clock.Now(),
-	}
-}
-
-func TestStore(t *testing.T) {
-
-	assertPostEqual := func(t *testing.T, exp, got StoredPost) {
-		t.Helper()
-		sort.Strings(exp.Tags)
-		sort.Strings(got.Tags)
-		assert.Equal(t, exp, got)
-	}
-
-	assertPostsEqual := func(t *testing.T, exp, got []StoredPost) {
-		t.Helper()
-
-		if !assert.Len(t, got, len(exp), "exp:%+v\ngot: %+v", exp, got) {
-			return
-		}
-
-		for i := range exp {
-			assertPostEqual(t, exp[i], got[i])
-		}
-	}
-
-	t.Run("not_found", func(t *testing.T) {
-		h := newStoreTestHarness(t)
-
-		_, err := h.store.GetByID("foo")
-		assert.ErrorIs(t, err, ErrNotFound)
-	})
-
-	t.Run("set_get_delete", func(t *testing.T) {
-		h := newStoreTestHarness(t)
-
-		now := h.clock.Now().UTC()
-
-		post := testPost(0)
-		post.Tags = []string{"foo", "bar"}
-
-		assert.NoError(t, h.store.Set(post, now))
-
-		gotPost, err := h.store.GetByID(post.ID)
-		assert.NoError(t, err)
-
-		assertPostEqual(t, StoredPost{
-			Post:        post,
-			PublishedAt: now,
-		}, gotPost)
-
-		// we will now try updating the post on a different day, and ensure it
-		// updates properly
-
-		h.clock.Add(24 * time.Hour)
-		newNow := h.clock.Now().UTC()
-
-		post.Title = "something else"
-		post.Series = "whatever"
-		post.Body = "anything"
-		post.Tags = []string{"bar", "baz"}
-
-		assert.NoError(t, h.store.Set(post, newNow))
-
-		gotPost, err = h.store.GetByID(post.ID)
-		assert.NoError(t, err)
-
-		assertPostEqual(t, StoredPost{
-			Post:          post,
-			PublishedAt:   now,
-			LastUpdatedAt: newNow,
-		}, gotPost)
-
-		// delete the post, it should go away
-		assert.NoError(t, h.store.Delete(post.ID))
-
-		_, err = h.store.GetByID(post.ID)
-		assert.ErrorIs(t, err, ErrNotFound)
-	})
-
-	t.Run("get", func(t *testing.T) {
-		h := newStoreTestHarness(t)
-
-		now := h.clock.Now().UTC()
-
-		posts := []StoredPost{
-			h.testStoredPost(0),
-			h.testStoredPost(1),
-			h.testStoredPost(2),
-			h.testStoredPost(3),
-		}
-
-		for _, post := range posts {
-			assert.NoError(t, h.store.Set(post.Post, now))
-		}
-
-		gotPosts, hasMore, err := h.store.Get(0, 2)
-		assert.NoError(t, err)
-		assert.True(t, hasMore)
-		assertPostsEqual(t, posts[:2], gotPosts)
-
-		gotPosts, hasMore, err = h.store.Get(1, 2)
-		assert.NoError(t, err)
-		assert.False(t, hasMore)
-		assertPostsEqual(t, posts[2:4], gotPosts)
-
-		posts = append(posts, h.testStoredPost(4))
-		assert.NoError(t, h.store.Set(posts[4].Post, now))
-
-		gotPosts, hasMore, err = h.store.Get(1, 2)
-		assert.NoError(t, err)
-		assert.True(t, hasMore)
-		assertPostsEqual(t, posts[2:4], gotPosts)
-
-		gotPosts, hasMore, err = h.store.Get(2, 2)
-		assert.NoError(t, err)
-		assert.False(t, hasMore)
-		assertPostsEqual(t, posts[4:], gotPosts)
-	})
-
-	t.Run("get_by_series", func(t *testing.T) {
-		h := newStoreTestHarness(t)
-
-		now := h.clock.Now().UTC()
-
-		posts := []StoredPost{
-			h.testStoredPost(0),
-			h.testStoredPost(1),
-			h.testStoredPost(2),
-			h.testStoredPost(3),
-		}
-
-		posts[0].Series = "foo"
-		posts[1].Series = "bar"
-		posts[2].Series = "bar"
-
-		for _, post := range posts {
-			assert.NoError(t, h.store.Set(post.Post, now))
-		}
-
-		fooPosts, err := h.store.GetBySeries("foo")
-		assert.NoError(t, err)
-		assertPostsEqual(t, posts[:1], fooPosts)
-
-		barPosts, err := h.store.GetBySeries("bar")
-		assert.NoError(t, err)
-		assertPostsEqual(t, posts[1:3], barPosts)
-
-		bazPosts, err := h.store.GetBySeries("baz")
-		assert.NoError(t, err)
-		assert.Empty(t, bazPosts)
-	})
-
-	t.Run("get_by_tag", func(t *testing.T) {
-
-		h := newStoreTestHarness(t)
-
-		now := h.clock.Now().UTC()
-
-		posts := []StoredPost{
-			h.testStoredPost(0),
-			h.testStoredPost(1),
-			h.testStoredPost(2),
-			h.testStoredPost(3),
-		}
-
-		posts[0].Tags = []string{"foo"}
-		posts[1].Tags = []string{"foo", "bar"}
-		posts[2].Tags = []string{"bar"}
-
-		for _, post := range posts {
-			assert.NoError(t, h.store.Set(post.Post, now))
-		}
-
-		fooPosts, err := h.store.GetByTag("foo")
-		assert.NoError(t, err)
-		assertPostsEqual(t, posts[:2], fooPosts)
-
-		barPosts, err := h.store.GetByTag("bar")
-		assert.NoError(t, err)
-		assertPostsEqual(t, posts[1:3], barPosts)
-
-		bazPosts, err := h.store.GetByTag("baz")
-		assert.NoError(t, err)
-		assert.Empty(t, bazPosts)
-	})
-}