General updates

.github/dependabot.yml

@@ -0,0 +1,10 @@
+version: 2
+updates:
+  - package-ecosystem: gomod
+    directory: "/"
+    schedule:
+      interval: daily
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: daily

GUIDE.md

@@ -0,0 +1 @@
+# Guide for oauth2

README.md

@@ -4,6 +4,7 @@
 [![pkg-img]][pkg-url]
 [![reportcard-img]][reportcard-url]
 [![coverage-img]][coverage-url]
+[![version-img]][version-url]
 
 OAuth2 client in Go.
 
@@ -13,9 +14,11 @@ OAuth2 client in Go.
 * Tiny codebase.
 * Dependency-free.
 
+See [GUIDE.md](https://github.com/cristalhq/oauth2/blob/main/GUIDE.md) for more details.
+
 ## Install
 
-Go version 1.13
+Go version 1.17
 
 ```
 go get github.com/cristalhq/oauth2
@@ -75,3 +78,5 @@ See [these docs][pkg-url].
 [reportcard-url]: https://goreportcard.com/report/cristalhq/oauth2
 [coverage-img]: https://codecov.io/gh/cristalhq/oauth2/branch/master/graph/badge.svg
 [coverage-url]: https://codecov.io/gh/cristalhq/oauth2
+[version-img]: https://img.shields.io/github/v/release/cristalhq/oauth2
+[version-url]: https://github.com/cristalhq/oauth2/releases

client.go

@@ -35,13 +35,11 @@ func NewClient(client *http.Client, config Config) *Client {
 // the state query parameter on your redirect callback.
 //
 // See http://tools.ietf.org/html/rfc6749#section-10.12 for more info.
-//
 func (c *Client) AuthCodeURL(state string) string {
 	return c.AuthCodeURLWithParams(state, nil)
 }
 
 // AuthCodeURLWithParams same as AuthCodeURL but allows to pass additional URL parameters.
-//
 func (c *Client) AuthCodeURLWithParams(state string, vals url.Values) string {
 	// TODO(cristaloleg): can be set once (except state).
 	v := cloneURLValues(vals)
@@ -72,13 +70,11 @@ func (c *Client) AuthCodeURLWithParams(state string, vals url.Values) string {
 }
 
 // Exchange converts an authorization code into an OAuth2 token.
-//
 func (c *Client) Exchange(ctx context.Context, code string) (*Token, error) {
 	return c.ExchangeWithParams(ctx, code, nil)
 }
 
 // ExchangeWithParams converts an authorization code into an OAuth2 token.
-//
 func (c *Client) ExchangeWithParams(ctx context.Context, code string, params url.Values) (*Token, error) {
 	vals := cloneURLValues(params)
 	vals.Add("grant_type", "authorization_code")
@@ -91,7 +87,6 @@ func (c *Client) ExchangeWithParams(ctx context.Context, code string, params url
 }
 
 // CredentialsToken retrieves a token for given username and password.
-//
 func (c *Client) CredentialsToken(ctx context.Context, username, password string) (*Token, error) {
 	vals := url.Values{
 		"grant_type": []string{"password"},
@@ -106,7 +101,6 @@ func (c *Client) CredentialsToken(ctx context.Context, username, password string
 }
 
 // Token renews a token based on previous token.
-//
 func (c *Client) Token(ctx context.Context, refreshToken string) (*Token, error) {
 	if refreshToken == "" {
 		return nil, errors.New("oauth2: refresh token is not set")
@@ -116,7 +110,6 @@ func (c *Client) Token(ctx context.Context, refreshToken string) (*Token, error)
 		"grant_type":    []string{"refresh_token"},
 		"refresh_token": []string{refreshToken},
 	}
-
 	return c.retrieveToken(ctx, vals)
 }
 
@@ -128,29 +121,30 @@ func (c *Client) retrieveToken(ctx context.Context, vals url.Values) (*Token, er
 		mode = InHeaderMode
 	}
 
-	token, err := c.makeRequest(ctx, mode, vals)
+	token, err := c.doRequest(ctx, mode, vals)
 	if err == nil {
+		c.config.Mode = mode
 		return token, nil
 	}
 	if !shouldGuessAuthMode {
 		return nil, err
 	}
 	mode = InParamsMode
 
-	token, err = c.makeRequest(ctx, mode, vals)
+	token, err = c.doRequest(ctx, mode, vals)
 	if err != nil {
 		return nil, err
 	}
 	c.config.Mode = mode
 	return token, nil
 }
 
-func (c *Client) makeRequest(ctx context.Context, mode Mode, vals url.Values) (*Token, error) {
-	req, err := c.newTokenRequest(mode, vals)
+func (c *Client) doRequest(ctx context.Context, mode Mode, vals url.Values) (*Token, error) {
+	req, err := c.newTokenRequest(ctx, mode, vals)
 	if err != nil {
 		return nil, err
 	}
-	resp, err := c.client.Do(req.WithContext(ctx))
+	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
@@ -161,7 +155,7 @@ func (c *Client) makeRequest(ctx context.Context, mode Mode, vals url.Values) (*
 	return token, nil
 }
 
-func (c *Client) newTokenRequest(mode Mode, v url.Values) (*http.Request, error) {
+func (c *Client) newTokenRequest(ctx context.Context, mode Mode, v url.Values) (*http.Request, error) {
 	clientID, clientSecret := c.config.ClientID, c.config.ClientSecret
 
 	if mode == InParamsMode {
@@ -174,7 +168,7 @@ func (c *Client) newTokenRequest(mode Mode, v url.Values) (*http.Request, error)
 		}
 	}
 
-	req, err := http.NewRequest("POST", c.config.TokenURL, strings.NewReader(v.Encode()))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.config.TokenURL, strings.NewReader(v.Encode()))
 	if err != nil {
 		return nil, err
 	}

client_test.go

@@ -387,7 +387,7 @@ func TestExchangeRequest_JSONResponse_Expiry(t *testing.T) {
 		true, false,
 	)
 	f(
-		fmt.Sprintf(`"expires_in": null`),
+		`"expires_in": null`,
 		true, true,
 	)
 	f(

example_test.go

@@ -14,8 +14,8 @@ func ExampleClientAndConfig() {
 	config := oauth2.Config{
 		ClientID:     "YOUR_CLIENT_ID",
 		ClientSecret: "YOUR_CLIENT_SECRET",
-		AuthURL:      "https://provider.com/o/oauth2/auth",
-		TokenURL:     "https://provider.com/o/oauth2/token",
+		AuthURL:      "https://example.com/o/oauth2/auth",
+		TokenURL:     "https://example.com/o/oauth2/token",
 		Scopes:       []string{"email", "avatar"},
 	}
 

go.mod

@@ -1,3 +1,3 @@
 module github.com/cristalhq/oauth2
 
-go 1.13
+go 1.17

utils.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"mime"
 	"net/http"
@@ -27,7 +26,7 @@ func cloneURLValues(vals url.Values) url.Values {
 }
 
 func parseResponse(resp *http.Response) (*Token, error) {
-	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
 	resp.Body.Close()
 
 	if err != nil {