added support for RemoveVertex, UpdateEdge, and EdgeCount

go.mod

@@ -4,11 +4,14 @@ go 1.18
 
 require (
 	github.com/Masterminds/squirrel v1.5.3
-	github.com/dominikbraun/graph v0.16.0
-	github.com/go-sql-driver/mysql v1.7.0
+	github.com/dominikbraun/graph v0.23.0
+	github.com/mattn/go-sqlite3 v1.14.17
+	github.com/stretchr/testify v1.2.2
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/lann/builder v0.0.0-20180802200727-47ae307949d0 // indirect
 	github.com/lann/ps v0.0.0-20150810152359-62de8c46ede0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 )

go.sum

@@ -2,14 +2,14 @@ github.com/Masterminds/squirrel v1.5.3 h1:YPpoceAcxuzIljlr5iWpNKaql7hLeG1KLSrhvd
 github.com/Masterminds/squirrel v1.5.3/go.mod h1:NNaOrjSoIDfDA40n7sr2tPNZRfjzjA400rg+riTZj10=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dominikbraun/graph v0.16.0 h1:M8B6g/uVYHQ2TG+AdbRtyXg7/ASHZCihzzkttFUHidA=
-github.com/dominikbraun/graph v0.16.0/go.mod h1:yOjYyogZLY1LSG9E33JWZJiq5k83Qy2C6POAuiViluc=
-github.com/go-sql-driver/mysql v1.7.0 h1:ueSltNNllEqE3qcWBTD0iQd3IpL/6U+mJxLkazJ7YPc=
-github.com/go-sql-driver/mysql v1.7.0/go.mod h1:OXbVy3sEdcQ2Doequ6Z5BW6fXNQTmx+9S1MCJN5yJMI=
+github.com/dominikbraun/graph v0.23.0 h1:TdZB4pPqCLFxYhdyMFb1TBdFxp8XLcJfTTBQucVPgCo=
+github.com/dominikbraun/graph v0.23.0/go.mod h1:yOjYyogZLY1LSG9E33JWZJiq5k83Qy2C6POAuiViluc=
 github.com/lann/builder v0.0.0-20180802200727-47ae307949d0 h1:SOEGU9fKiNWd/HOJuq6+3iTQz8KNCLtVX6idSoTLdUw=
 github.com/lann/builder v0.0.0-20180802200727-47ae307949d0/go.mod h1:dXGbAdH5GtBTC4WfIxhKZfyBF/HBFgRZSWwZ9g/He9o=
 github.com/lann/ps v0.0.0-20150810152359-62de8c46ede0 h1:P6pPBnrTSX3DEVR4fDembhRWSsG5rVo6hYhAB/ADZrk=
 github.com/lann/ps v0.0.0-20150810152359-62de8c46ede0/go.mod h1:vmVJ0l/dxyfGW6FmdpVm2joNMFikkuWg0EoCKLGUMNw=
+github.com/mattn/go-sqlite3 v1.14.17 h1:mCRHCLDUBXgpKAqIKsaAaAsrAlbkeomtRFKXh2L6YIM=
+github.com/mattn/go-sqlite3 v1.14.17/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=

store.go

@@ -79,6 +79,19 @@ func (s *Store[K, T]) AddVertex(hash K, value T, properties graph.VertexProperti
 	return err
 }
 
+// RemoveVertex implements graph.Store.RemoveVertex.
+func (s *Store[K, T]) RemoveVertex(hash K) error {
+	_, err := sq.
+		Delete(s.config.VerticesTable).
+		Where(sq.Eq{
+			"hash": hash,
+		}).
+		RunWith(s.db).
+		Exec()
+
+	return err
+}
+
 // Vertex implements graph.Store.Vertex.
 func (s *Store[K, T]) Vertex(hash K) (T, graph.VertexProperties, error) {
 	var (
@@ -217,6 +230,10 @@ func (s *Store[K, T]) Edge(sourceHash, targetHash K) (graph.Edge[K], error) {
 		return edge, graph.ErrEdgeNotFound
 	}
 
+	if err != nil {
+		return edge, fmt.Errorf("failed to scan row: %w", err)
+	}
+
 	if err = json.Unmarshal(attributesBytes, &edge.Properties.Attributes); err != nil {
 		return edge, fmt.Errorf("failed to unmarshal attributes: %w", err)
 	}
@@ -269,3 +286,37 @@ func (s *Store[K, T]) ListEdges() ([]graph.Edge[K], error) {
 
 	return edges, nil
 }
+
+// EdgeCount implements graph.Store.EdgeCount.
+func (s *Store[K, T]) EdgeCount() (int, error) {
+	var count int
+
+	// Please note that for some reason count(id) does not return the correct results for sqlite.
+	err := sq.
+		Select("count(source_hash)").
+		From(s.config.EdgesTable).
+		RunWith(s.db).
+		QueryRow().
+		Scan(&count)
+
+	return count, err
+}
+
+func (s *Store[K, T]) UpdateEdge(sourceHash, targetHash K, edge graph.Edge[K]) error {
+
+	attributesBytes, err := json.Marshal(edge.Properties.Attributes)
+	if err != nil {
+		return err
+	}
+
+	_, err = sq.Update(s.config.EdgesTable).
+		Set("weight", edge.Properties.Weight).
+		Set("attributes", attributesBytes).
+		Set("data", edge.Properties.Data).
+		Where("source_hash = ?", sourceHash).
+		Where("target_hash = ?", targetHash).
+		RunWith(s.db).
+		Exec()
+
+	return err
+}

store_test.go

@@ -0,0 +1,159 @@
+package graphsql
+
+import (
+	"database/sql"
+	"fmt"
+
+	"testing"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/dominikbraun/graph"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func createStore[K comparable, T any]() (*Store[K, T], error) {
+
+	db, err := sql.Open("sqlite3", "file::memory:")
+	if err != nil {
+		panic(err)
+	}
+
+	store := New[K, T](db, DefaultConfig)
+	if store == nil {
+		return nil, fmt.Errorf("failed to create new store")
+	}
+
+	if err := store.SetupTables(); err != nil {
+		return nil, err
+	}
+
+	return store, nil
+}
+
+func TestImplementsStoreInterface(t *testing.T) {
+
+	var store = Store[int, int]{}
+
+	// this will throw a compile error if graphsql.Store doesn't implement the graph.Store interface
+	var _ graph.Store[int, int] = (*Store[int, int])(&store)
+}
+
+func TestEdgeCount(t *testing.T) {
+
+	assert := assert.New(t)
+
+	store, err := createStore[int, int]()
+	assert.Nil(err)
+	assert.NotNil(store)
+
+	store.AddVertex(1, 1, graph.VertexProperties{})
+	store.AddVertex(2, 2, graph.VertexProperties{})
+
+	edgeCount, err := store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(0, edgeCount)
+
+	store.AddEdge(1, 2, graph.Edge[int]{ 1, 2, graph.EdgeProperties{} })
+
+	edgeCount, err = store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(1, edgeCount)
+
+	store.AddEdge(2, 1, graph.Edge[int]{ 2, 1, graph.EdgeProperties{} })
+
+	edgeCount, err = store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(2, edgeCount)
+
+	store.AddEdge(1, 1, graph.Edge[int]{ 1, 1, graph.EdgeProperties{} })
+
+	edgeCount, err = store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(3, edgeCount)
+
+	store.AddEdge(2, 2, graph.Edge[int]{ 2, 2, graph.EdgeProperties{} })
+
+	edgeCount, err = store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(4, edgeCount)
+
+	store.RemoveEdge(2, 2)
+
+	edgeCount, err = store.EdgeCount()
+	assert.Nil(err)
+	assert.Equal(3, edgeCount)
+}
+
+func TestRemoveVertex(t *testing.T) {
+
+	assert := assert.New(t)
+
+	store, err := createStore[int, int]()
+	assert.Nil(err)
+	assert.NotNil(store)
+
+	store.AddVertex(1, 1, graph.VertexProperties{})
+
+	vertexCount, err := store.VertexCount()
+	assert.Nil(err)
+	assert.Equal(1, vertexCount)
+
+	err = store.RemoveVertex(1)
+	assert.Nil(err)
+
+	vertexCount, err = store.VertexCount()
+	assert.Nil(err)
+	assert.Equal(0, vertexCount)
+
+	// larger graph
+	store.AddVertex(1, 1, graph.VertexProperties{})
+	store.AddVertex(2, 2, graph.VertexProperties{})
+	store.AddVertex(3, 3, graph.VertexProperties{})
+	store.AddVertex(4, 4, graph.VertexProperties{})
+
+	vertexCount, err = store.VertexCount()
+	assert.Nil(err)
+	assert.Equal(4, vertexCount)
+
+	err = store.RemoveVertex(3)
+	assert.Nil(err)
+
+	vertexCount, err = store.VertexCount()
+	assert.Nil(err)
+	assert.Equal(3, vertexCount)
+
+	_, _, err = store.Vertex(3)
+	assert.NotNil(err)
+}
+
+func TestUpdateEdge(t *testing.T) {
+
+	assert := assert.New(t)
+
+	store, err := createStore[int, int]()
+	assert.Nil(err)
+	assert.NotNil(store)
+
+	store.AddVertex(1, 1, graph.VertexProperties{})
+	store.AddVertex(2, 2, graph.VertexProperties{})
+
+	store.AddEdge(1, 2, graph.Edge[int]{ 1, 2, graph.EdgeProperties{} })
+	store.AddEdge(2, 1, graph.Edge[int]{ 2, 1, graph.EdgeProperties{} })
+	store.AddEdge(1, 1, graph.Edge[int]{ 1, 1, graph.EdgeProperties{} })
+	store.AddEdge(2, 2, graph.Edge[int]{ 2, 2, graph.EdgeProperties{} })
+
+	err = store.UpdateEdge(1, 1, graph.Edge[int]{ 1, 1, graph.EdgeProperties{
+		Attributes: map[string]string{ "abc": "xyz"},
+		Weight: 5,
+		Data: "happy",
+	}})
+
+	assert.Nil(err)
+
+	edge, err := store.Edge(1, 1)
+	assert.Nil(err)
+	assert.Equal(5, edge.Properties.Weight)
+	assert.Equal("xyz", edge.Properties.Attributes["abc"])
+	assert.Equal("happy", edge.Properties.Data)
+}