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VTN-29032, create interface to graphql client
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@ctsiokos-veritone
ctsiokos-veritone committed Aug 29, 2019
1 parent 41fe1d0 commit 6e5411f
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Showing 3 changed files with 78 additions and 42 deletions.
57 changes: 31 additions & 26 deletions graphql.go
View file
Expand Up @@ -48,25 +48,26 @@ import (
"github.com/pkg/errors"
)

type Client interface {
Run(ctx context.Context, req *Request, resp interface{}) error
SetLogger(func(string))
}

// Client is a client for interacting with a GraphQL API.
type Client struct {
type clientImp struct {
endpoint string
httpClient *http.Client
useMultipartForm bool
retryConfig RetryConfig
defaultHeaders map[string]string

// Log is called with various debug information.
// To log to standard out, use:
// client.Log = func(s string) { log.Println(s) }
Log func(s string)
log func(s string)
}

// NewClient makes a new Client capable of making GraphQL requests.
func NewClient(endpoint string, opts ...ClientOption) *Client {
c := &Client{
func NewClient(endpoint string, opts ...ClientOption) Client {
c := &clientImp{
endpoint: endpoint,
Log: func(string) {},
log: func(string) {},
}
for _, optionFunc := range opts {
optionFunc(c)
Expand All @@ -80,8 +81,12 @@ func NewClient(endpoint string, opts ...ClientOption) *Client {
return c
}

func (c *Client) logf(format string, args ...interface{}) {
c.Log(fmt.Sprintf(format, args...))
func (c *clientImp) SetLogger(cb func(string)) {
c.log = cb
}

func (c *clientImp) logf(format string, args ...interface{}) {
c.log(fmt.Sprintf(format, args...))
}

// RetryConfig defines possible fields that client can supply for their retry strategies
Expand Down Expand Up @@ -131,7 +136,7 @@ var (
)

// Wrapper method to send request while optionally applying retry policy
func (c *Client) sendRequest(retryConfig *RetryConfig, req *http.Request) (*http.Response, error) {
func (c *clientImp) sendRequest(retryConfig *RetryConfig, req *http.Request) (*http.Response, error) {
// Client did not specify retry config
if retryConfig.Policy == "" {
resp, err := c.httpClient.Do(req)
Expand Down Expand Up @@ -230,35 +235,35 @@ func (config *RetryConfig) isValid() bool {

// WithRetryConfig allows consumer to assign their retryConfig to the client's private retryConfig
func WithRetryConfig(config RetryConfig) ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.retryConfig = config
}
}

// WithDefaultLinearRetryConfig provides a default set of value for linear policy
func WithDefaultLinearRetryConfig() ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.retryConfig = defaultLinearRetryConfig
}
}

// WithDefaultExponentialRetryConfig provides a default set of value for exponential backoff policy
func WithDefaultExponentialRetryConfig() ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.retryConfig = defaultExponentialRetryConfig
}
}

// WithBeforeRetryHandler provides a handler for beforeRetry
func WithBeforeRetryHandler(beforeRetryHandler func(*http.Request, *http.Response, error, int)) ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.retryConfig.BeforeRetry = beforeRetryHandler
}
}

// WithDefaultHeaders provides a default set of header values
func WithDefaultHeaders(defaultHeaders map[string]string) ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.defaultHeaders = defaultHeaders
}
}
Expand All @@ -268,7 +273,7 @@ func WithDefaultHeaders(defaultHeaders map[string]string) ClientOption {
// Pass in a nil response object to skip response parsing.
// If the request fails or the server returns an error, the first error
// will be returned.
func (c *Client) Run(ctx context.Context, req *Request, resp interface{}) error {
func (c *clientImp) Run(ctx context.Context, req *Request, resp interface{}) error {
// TODO: validate retryConfig

select {
Expand All @@ -285,7 +290,7 @@ func (c *Client) Run(ctx context.Context, req *Request, resp interface{}) error
return c.runWithJSON(ctx, req, resp)
}

func (c *Client) getTracer() *httptrace.ClientTrace {
func (c *clientImp) getTracer() *httptrace.ClientTrace {
trace := &httptrace.ClientTrace{
GotConn: func(connInfo httptrace.GotConnInfo) {
c.logf("Connection reused? %t", connInfo.Reused)
Expand Down Expand Up @@ -323,7 +328,7 @@ func (c *Client) getTracer() *httptrace.ClientTrace {
return trace
}

func (c *Client) runWithJSON(ctx context.Context, req *Request, resp interface{}) error {
func (c *clientImp) runWithJSON(ctx context.Context, req *Request, resp interface{}) error {
var requestBody bytes.Buffer
requestBodyObj := struct {
Query string `json:"query"`
Expand Down Expand Up @@ -376,7 +381,7 @@ func getGraphQLResp(reader io.ReadCloser, schema interface{}) error {
return nil
}

func (c *Client) executeRequest(gr *graphResponse, r *http.Request) error {
func (c *clientImp) executeRequest(gr *graphResponse, r *http.Request) error {
gqlRetryConfig := c.retryConfig
var body io.Reader = r.Body
tryCount := 0
Expand Down Expand Up @@ -415,7 +420,7 @@ func (c *Client) executeRequest(gr *graphResponse, r *http.Request) error {
}

} else {
c.Log("debug return error")
c.log("debug return error")
return getAggrErr(gr.Errors)
}

Expand All @@ -428,7 +433,7 @@ func (c *Client) executeRequest(gr *graphResponse, r *http.Request) error {
return fmt.Errorf("Client has retried %d times but unable to get a successful response. Error: %s", tryCount, getAggrErr(gr.Errors))
}

func (c *Client) runWithPostFields(ctx context.Context, req *Request, resp interface{}) error {
func (c *clientImp) runWithPostFields(ctx context.Context, req *Request, resp interface{}) error {
var requestBody bytes.Buffer
writer := multipart.NewWriter(&requestBody)
if err := writer.WriteField("query", req.q); err != nil {
Expand Down Expand Up @@ -488,22 +493,22 @@ func (c *Client) runWithPostFields(ctx context.Context, req *Request, resp inter
// making requests.
// NewClient(endpoint, WithHTTPClient(specificHTTPClient))
func WithHTTPClient(httpclient *http.Client) ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.httpClient = httpclient
}
}

// UseMultipartForm uses multipart/form-data and activates support for
// files.
func UseMultipartForm() ClientOption {
return func(client *Client) {
return func(client *clientImp) {
client.useMultipartForm = true
}
}

// ClientOption are functions that are passed into NewClient to
// modify the behaviour of the Client.
type ClientOption func(*Client)
type ClientOption func(*clientImp)

type graphResponse struct {
Data interface{}
Expand Down
32 changes: 16 additions & 16 deletions graphql_retry_test.go
View file
Expand Up @@ -27,9 +27,9 @@ func TestLinearPolicy(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL, WithDefaultLinearRetryConfig())
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(10))
defer cancel()
Expand All @@ -50,9 +50,9 @@ func TestNilRespStatus200(t *testing.T) {
defer srv.Close()

client := NewClient(srv.URL, WithDefaultLinearRetryConfig())
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

var responseData map[string]interface{}
err := client.Run(context.Background(), &Request{q: "query {}"}, &responseData)
Expand All @@ -79,9 +79,9 @@ func TestNoPolicySpecified(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL)
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(1))
defer cancel()
Expand Down Expand Up @@ -109,9 +109,9 @@ func TestCustomRetryStatus(t *testing.T) {
RetryStatus: retryStatus,
}
client := NewClient(srv.URL, WithRetryConfig(retryConfig))
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(1))
defer cancel()
Expand All @@ -132,9 +132,9 @@ func TestExponentialBackoffPolicy(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL, WithDefaultExponentialRetryConfig(), WithBeforeRetryHandler(logHandler(t)))
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(31))
defer cancel()
Expand Down Expand Up @@ -164,9 +164,9 @@ func TestExponentialBackoffPolicyMultiPart(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL, WithDefaultExponentialRetryConfig(), WithBeforeRetryHandler(logHandler(t)), UseMultipartForm())
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(31))
defer cancel()
Expand Down Expand Up @@ -214,9 +214,9 @@ func TestErrCodeRetry(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL, WithDefaultExponentialRetryConfig(), WithBeforeRetryHandler(logHandler(t)), UseMultipartForm())
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(31))
defer cancel()
Expand Down Expand Up @@ -257,9 +257,9 @@ func TestErrCodeNoRetry(t *testing.T) {

ctx := context.Background()
client := NewClient(srv.URL, WithDefaultExponentialRetryConfig(), WithBeforeRetryHandler(logHandler(t)), UseMultipartForm())
client.Log = func(str string) {
client.SetLogger(func(str string) {
t.Log(str)
}
})

ctx, cancel := context.WithTimeout(ctx, getTestDuration(31))
defer cancel()
Expand Down
31 changes: 31 additions & 0 deletions mocks/Client.go
View file

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