cqrs: base package
This commit is contained in:
parent
636b2dbf8f
commit
76dea96a46
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@ -0,0 +1,92 @@
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package cqrs
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import (
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"context"
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)
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type Bus struct {
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reg *Registry
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cmdFactory CommandFactory
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cmdResultFactory CommandResultFactory
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qryFactory QueryFactory
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qryResultFactory QueryResultFactory
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}
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func (b *Bus) Exec(ctx context.Context, req CommandRequest) (CommandResult, error) {
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cmd, err := b.cmdFactory(req)
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if err != nil {
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return nil, err
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}
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hdlr, mdlwrs, err := b.reg.MatchCommand(cmd)
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if err != nil {
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return nil, err
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}
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if len(mdlwrs) > 0 {
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for i := len(mdlwrs) - 1; i >= 0; i-- {
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hdlr = mdlwrs[i](hdlr)
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}
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}
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if err := hdlr.Handle(ctx, cmd); err != nil {
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return nil, err
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}
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result, err := b.cmdResultFactory(cmd)
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if err != nil {
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return nil, err
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}
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return result, nil
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}
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func (b *Bus) Query(ctx context.Context, req QueryRequest) (QueryResult, error) {
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qry, err := b.qryFactory(req)
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if err != nil {
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return nil, err
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}
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hdlr, mdlwrs, err := b.reg.MatchQuery(qry)
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if err != nil {
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return nil, err
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}
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if len(mdlwrs) > 0 {
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for i := len(mdlwrs) - 1; i >= 0; i-- {
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hdlr = mdlwrs[i](hdlr)
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}
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}
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data, err := hdlr.Handle(ctx, qry)
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if err != nil {
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return nil, err
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}
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result, err := b.qryResultFactory(qry, data)
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if err != nil {
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return nil, err
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}
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return result, nil
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}
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func (b *Bus) RegisterCommand(match MatchFunc, hdlr CommandHandler, mdlwrs ...CommandMiddleware) {
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b.reg.RegisterCommand(match, hdlr, mdlwrs...)
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}
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func (b *Bus) RegisterQuery(match MatchFunc, hdlr QueryHandler, mdlwrs ...QueryMiddleware) {
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b.reg.RegisterQuery(match, hdlr, mdlwrs...)
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}
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func NewBus(funcs ...OptionFunc) *Bus {
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opt := CreateOption(funcs...)
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return &Bus{
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reg: NewRegistry(),
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cmdFactory: opt.CommandFactory,
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cmdResultFactory: opt.CommandResultFactory,
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qryFactory: opt.QueryFactory,
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qryResultFactory: opt.QueryResultFactory,
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}
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}
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@ -0,0 +1,52 @@
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package cqrs
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import (
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"context"
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"testing"
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)
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type testCommandRequest struct {
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Foo string
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}
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func TestSimpleCommandExec(t *testing.T) {
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bus := NewBus()
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handlerCalled := false
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handleTestCommand := func(ctx context.Context, cmd Command) error {
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handlerCalled = true
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return nil
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}
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bus.RegisterCommand(
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MatchCommandRequest(&testCommandRequest{}),
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CommandHandlerFunc(handleTestCommand),
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)
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cmd := &testCommandRequest{
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Foo: "bar",
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}
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ctx := context.Background()
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result, err := bus.Exec(ctx, cmd)
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if err != nil {
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t.Error(err)
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}
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if result == nil {
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t.Error("result should not be nil")
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}
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if result.Command() == nil {
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t.Error("result.Command() should not be nil")
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}
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if e, g := result.Command().Request(), cmd; e != g {
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t.Errorf("result.Command().Request(): expected '%v', got '%v'", e, g)
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}
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if e, g := handlerCalled, true; e != g {
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t.Errorf("handlerCalled: expected '%v', got '%v'", e, g)
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}
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}
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@ -0,0 +1,61 @@
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package cqrs
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import (
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"context"
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"github.com/google/uuid"
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)
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type CommandID string
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type CommandRequest interface {
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}
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type Command interface {
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ID() CommandID
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Request() CommandRequest
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}
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type BaseCommand struct {
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id CommandID
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req CommandRequest
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}
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func (c *BaseCommand) ID() CommandID {
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return c.id
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}
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func (c *BaseCommand) Request() CommandRequest {
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return c.req
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}
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func NewBaseCommand(req CommandRequest) *BaseCommand {
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id := CommandID(uuid.New().String())
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return &BaseCommand{id, req}
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}
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type CommandResult interface {
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Command() Command
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}
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type BaseCommandResult struct {
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cmd Command
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}
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func (r *BaseCommandResult) Command() Command {
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return r.cmd
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}
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func NewBaseCommandResult(cmd Command) *BaseCommandResult {
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return &BaseCommandResult{cmd}
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}
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type CommandHandlerFunc func(context.Context, Command) error
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func (h CommandHandlerFunc) Handle(ctx context.Context, cmd Command) error {
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return h(ctx, cmd)
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}
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type CommandHandler interface {
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Handle(context.Context, Command) error
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}
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@ -0,0 +1,9 @@
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package cqrs
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import "errors"
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var (
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ErrInvalidRequestType = errors.New("invalid request type")
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ErrHandlerNotFound = errors.New("handler not found")
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ErrUnexpectedRequest = errors.New("unexpected request")
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)
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@ -0,0 +1,33 @@
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package cqrs
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import (
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"reflect"
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)
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type MatchFunc func(interface{}) (bool, error)
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func MatchCommandRequest(req interface{}) MatchFunc {
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reqType := reflect.TypeOf(req)
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return func(raw interface{}) (bool, error) {
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cmd, ok := raw.(Command)
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if !ok {
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return false, ErrInvalidRequestType
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}
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return reflect.TypeOf(cmd.Request()) == reqType, nil
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}
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}
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func MatchQueryRequest(req interface{}) MatchFunc {
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reqType := reflect.TypeOf(req)
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return func(raw interface{}) (bool, error) {
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cmd, ok := raw.(Query)
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if !ok {
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return false, ErrInvalidRequestType
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}
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return reflect.TypeOf(cmd.Request()) == reqType, nil
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}
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}
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package cqrs
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import "testing"
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type testType struct{}
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func TestMatchCommandRequestType(t *testing.T) {
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match := MatchCommandRequest(&testType{})
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cmd := NewBaseCommand(&testType{})
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matches, err := match(cmd)
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if err != nil {
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t.Error(err)
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}
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if e, g := true, matches; e != g {
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t.Errorf("match(&testType{}): expected '%v', got '%v'", e, g)
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}
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cmd = NewBaseCommand(nil)
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matches, err = match(cmd)
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if err != nil {
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t.Error(err)
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}
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if e, g := false, matches; e != g {
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t.Errorf("match(nil): expected '%v', got '%v'", e, g)
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}
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cmd = NewBaseCommand("test")
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matches, err = match(cmd)
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if err != nil {
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t.Error(err)
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}
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if e, g := false, matches; e != g {
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t.Errorf("match(\"test\"): expected '%v', got '%v'", e, g)
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}
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}
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package cqrs
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import (
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"context"
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"testing"
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)
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func TestBasicCommandMiddleware(t *testing.T) {
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bus := NewBus()
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handlerCalled := false
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handleTestCommand := func(ctx context.Context, cmd Command) error {
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handlerCalled = true
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return nil
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}
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middlewareCalled := false
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commandMiddleware := func(next CommandHandler) CommandHandler {
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fn := func(ctx context.Context, cmd Command) error {
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middlewareCalled = true
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return next.Handle(ctx, cmd)
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}
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return CommandHandlerFunc(fn)
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}
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bus.RegisterCommand(
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MatchCommandRequest(&testCommandRequest{}),
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CommandHandlerFunc(handleTestCommand),
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commandMiddleware,
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)
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cmd := &testCommandRequest{
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Foo: "bar",
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}
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ctx := context.Background()
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result, err := bus.Exec(ctx, cmd)
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if err != nil {
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t.Error(err)
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}
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if result == nil {
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t.Error("result should not be nil")
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}
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if result.Command() == nil {
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t.Error("result.Command() should not be nil")
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}
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if e, g := result.Command().Request(), cmd; e != g {
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t.Errorf("result.Command().Request(): expected '%v', got '%v'", e, g)
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}
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if e, g := middlewareCalled, true; e != g {
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t.Errorf("middlewareCalled: expected '%v', got '%v'", e, g)
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}
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if e, g := handlerCalled, true; e != g {
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t.Errorf("handlerCalled: expected '%v', got '%v'", e, g)
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}
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}
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@ -0,0 +1,86 @@
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package cqrs
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type Option struct {
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CommandFactory CommandFactory
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QueryFactory QueryFactory
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CommandResultFactory CommandResultFactory
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QueryResultFactory QueryResultFactory
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}
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type CommandFactory func(CommandRequest) (Command, error)
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type QueryFactory func(QueryRequest) (Query, error)
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type CommandResultFactory func(Command) (CommandResult, error)
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type QueryResultFactory func(Query, interface{}) (QueryResult, error)
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type OptionFunc func(*Option)
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func DefaultOption() *Option {
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funcs := []OptionFunc{
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WithBaseQueryFactory(),
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WithBaseCommandFactory(),
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WithBaseQueryResultFactory(),
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WithBaseCommandResultFactory(),
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}
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opt := &Option{}
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for _, fn := range funcs {
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fn(opt)
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}
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return opt
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}
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func CreateOption(funcs ...OptionFunc) *Option {
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opt := DefaultOption()
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for _, fn := range funcs {
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fn(opt)
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}
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return opt
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}
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func WithCommandFactory(factory CommandFactory) OptionFunc {
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return func(opt *Option) {
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opt.CommandFactory = factory
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}
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}
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func WithQueryFactory(factory QueryFactory) OptionFunc {
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return func(opt *Option) {
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opt.QueryFactory = factory
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}
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}
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func WithBaseQueryFactory() OptionFunc {
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return func(opt *Option) {
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opt.QueryFactory = func(req QueryRequest) (Query, error) {
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return NewBaseQuery(req), nil
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}
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}
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}
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func WithBaseCommandFactory() OptionFunc {
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return func(opt *Option) {
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opt.CommandFactory = func(req CommandRequest) (Command, error) {
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return NewBaseCommand(req), nil
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}
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}
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}
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func WithBaseQueryResultFactory() OptionFunc {
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return func(opt *Option) {
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opt.QueryResultFactory = func(qry Query, data interface{}) (QueryResult, error) {
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return NewBaseQueryResult(qry, data), nil
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}
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}
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}
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func WithBaseCommandResultFactory() OptionFunc {
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return func(opt *Option) {
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opt.CommandResultFactory = func(cmd Command) (CommandResult, error) {
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return NewBaseCommandResult(cmd), nil
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}
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}
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}
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@ -0,0 +1,13 @@
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package cqrs
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import "gitlab.com/wpetit/goweb/service"
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// ServiceProvider returns a service.Provider for the
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// the cqrs service
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func ServiceProvider() service.Provider {
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bus := NewBus()
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return func(container *service.Container) (interface{}, error) {
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return bus, nil
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}
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}
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@ -0,0 +1,66 @@
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package cqrs
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import (
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"context"
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"github.com/google/uuid"
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)
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type QueryID string
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type QueryRequest interface{}
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type Query interface {
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ID() QueryID
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Request() QueryRequest
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}
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type BaseQuery struct {
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id QueryID
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req QueryRequest
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}
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func (q *BaseQuery) ID() QueryID {
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return q.id
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}
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func (q *BaseQuery) Request() QueryRequest {
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return q.req
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}
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func NewBaseQuery(req QueryRequest) *BaseQuery {
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id := QueryID(uuid.New().String())
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return &BaseQuery{id, req}
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}
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type QueryResult interface {
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Query() Query
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Data() interface{}
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}
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type BaseQueryResult struct {
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qry Query
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data interface{}
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}
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func (r *BaseQueryResult) Query() Query {
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return r.qry
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}
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func (r *BaseQueryResult) Data() interface{} {
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return r.data
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}
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func NewBaseQueryResult(qry Query, data interface{}) *BaseQueryResult {
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return &BaseQueryResult{qry, data}
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}
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type QueryHandlerFunc func(context.Context, Query) (interface{}, error)
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func (h QueryHandlerFunc) Handle(ctx context.Context, qry Query) (interface{}, error) {
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return h(ctx, qry)
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}
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type QueryHandler interface {
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Handle(context.Context, Query) (interface{}, error)
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}
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@ -0,0 +1,68 @@
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package cqrs
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type CommandMiddleware func(next CommandHandler) CommandHandler
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type QueryMiddleware func(next QueryHandler) QueryHandler
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type Registry struct {
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commands []*commandHandler
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queries []*queryHandler
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}
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type commandHandler struct {
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Match MatchFunc
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Handler CommandHandler
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Middlewares []CommandMiddleware
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}
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type queryHandler struct {
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Match MatchFunc
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Handler QueryHandler
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Middlewares []QueryMiddleware
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}
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func (r *Registry) MatchCommand(cmd Command) (CommandHandler, []CommandMiddleware, error) {
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// TODO cache matching to avoid unnecessary ops
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for _, reg := range r.commands {
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matches, err := reg.Match(cmd)
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if err != nil {
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return nil, nil, err
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}
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if matches {
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return reg.Handler, reg.Middlewares, nil
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}
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}
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return nil, nil, ErrHandlerNotFound
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}
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func (r *Registry) MatchQuery(qry Query) (QueryHandler, []QueryMiddleware, error) {
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// TODO cache matching to avoid unnecessary ops
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for _, reg := range r.queries {
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matches, err := reg.Match(qry)
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if err != nil {
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return nil, nil, err
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}
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|
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if matches {
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return reg.Handler, reg.Middlewares, nil
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}
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}
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return nil, nil, ErrHandlerNotFound
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}
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func (r *Registry) RegisterCommand(match MatchFunc, hdlr CommandHandler, mdlwrs ...CommandMiddleware) {
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r.commands = append(r.commands, &commandHandler{match, hdlr, mdlwrs})
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}
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func (r *Registry) RegisterQuery(match MatchFunc, hdlr QueryHandler, mdlwrs ...QueryMiddleware) {
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r.queries = append(r.queries, &queryHandler{match, hdlr, mdlwrs})
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}
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|
||||
func NewRegistry() *Registry {
|
||||
return &Registry{
|
||||
commands: make([]*commandHandler, 0),
|
||||
queries: make([]*queryHandler, 0),
|
||||
}
|
||||
}
|
|
@ -0,0 +1,34 @@
|
|||
package cqrs
|
||||
|
||||
import (
|
||||
"github.com/pkg/errors"
|
||||
"gitlab.com/wpetit/goweb/service"
|
||||
)
|
||||
|
||||
// ServiceName defines the cqrs service name
|
||||
const ServiceName service.Name = "cqrs"
|
||||
|
||||
// From retrieves the cqrs service in the given container
|
||||
func From(container *service.Container) (*Bus, error) {
|
||||
raw, err := container.Service(ServiceName)
|
||||
if err != nil {
|
||||
return nil, errors.Wrapf(err, "error while retrieving '%s' service", ServiceName)
|
||||
}
|
||||
|
||||
srv, ok := raw.(*Bus)
|
||||
if !ok {
|
||||
return nil, errors.Errorf("retrieved service is not a valid '%s' service", ServiceName)
|
||||
}
|
||||
|
||||
return srv, nil
|
||||
}
|
||||
|
||||
// Must retrieves the cqrs service in the given container or panic otherwise
|
||||
func Must(container *service.Container) *Bus {
|
||||
service, err := From(container)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
return service
|
||||
}
|
2
go.mod
2
go.mod
|
@ -4,9 +4,11 @@ go 1.12
|
|||
|
||||
require (
|
||||
cdr.dev/slog v1.3.0
|
||||
github.com/davecgh/go-spew v1.1.1
|
||||
github.com/go-chi/chi v4.0.2+incompatible
|
||||
github.com/go-playground/locales v0.12.1 // indirect
|
||||
github.com/go-playground/universal-translator v0.16.0 // indirect
|
||||
github.com/google/uuid v1.1.1
|
||||
github.com/gorilla/securecookie v1.1.1
|
||||
github.com/gorilla/sessions v1.2.0
|
||||
github.com/leodido/go-urn v1.1.0 // indirect
|
||||
|
|
2
go.sum
2
go.sum
|
@ -68,6 +68,8 @@ github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXi
|
|||
github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
|
||||
github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
|
||||
github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
|
||||
github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
|
||||
github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
|
||||
github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
|
||||
github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
|
||||
github.com/gorilla/csrf v1.6.0/go.mod h1:7tSf8kmjNYr7IWDCYhd3U8Ck34iQ/Yw5CJu7bAkHEGI=
|
||||
|
|
Loading…
Reference in New Issue