adds HttpPutJSON() and HttpPostJSON() (#4)

json.go

@@ -1,6 +1,7 @@
 package gotoolbox
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -31,19 +32,68 @@ func ReadJSONFile(fileName string) (map[string]string, error) {
 // HttpGetJSON fetches the contents of the given URL
 // and decodes it as JSON into the given result,
 // which should be a pointer to the expected data.
+// returns an error if http response code is not 200
 func HttpGetJSON(url string, result interface{}) error {
 
 	resp, err := http.Get(url)
 	if err != nil {
-		return fmt.Errorf("cannot fetch URL %q: %v", url, err)
+		return fmt.Errorf("cannot fetch URL %q: %w", url, err)
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		return fmt.Errorf("unexpected http GET status: %s", resp.Status)
 	}
 	err = json.NewDecoder(resp.Body).Decode(result)
 	if err != nil {
-		return fmt.Errorf("cannot decode JSON: %v", err)
+		return fmt.Errorf("cannot decode JSON: %w", err)
+	}
+	return nil
+}
+
+// HttpPutJSON encodes a struct as JSON and
+// HTTP PUTs it to the specified endpoint
+// returns an error if http response code is not 200
+func HttpPutJSON(url string, o interface{}) error {
+
+	payload := new(bytes.Buffer)
+	json.NewEncoder(payload).Encode(o)
+	req, err := http.NewRequest(http.MethodPut, url, payload)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("unexpected http PUT error: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("unexpected http PUT status: %s", resp.Status)
+	}
+	return nil
+}
+
+// HttpPostJSON encodes a struct as JSON and
+// HTTP POSTs it to the specified endpoint
+// returns an error if http response code does not match specified
+func HttpPostJSON(url string, o interface{}, httpStatusCodeToCheck int) error {
+
+	payload := new(bytes.Buffer)
+	json.NewEncoder(payload).Encode(o)
+	req, err := http.NewRequest(http.MethodPost, url, payload)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("unexpected http PUT error: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != httpStatusCodeToCheck {
+		return fmt.Errorf("unexpected http POST status: %s", resp.Status)
 	}
 	return nil
 }