refactor: remove duplicated post code

Give the tado client a central post method that all setter functions
can rely on.

client.go

@@ -112,6 +112,23 @@ func (c *Client) get(url string, v interface{}) error {
 	return nil
 }
 
+// post sends a post request to the tado° API.
+func (c *Client) post(url string) error {
+	resp, err := c.Request(http.MethodPost, url, nil)
+	if err != nil {
+		return err
+	}
+
+	if err := isError(resp); err != nil {
+		return fmt.Errorf("tado° API error: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusNoContent {
+		return fmt.Errorf("unexpected tado° API response status: %s", resp.Status)
+	}
+	return nil
+}
+
 // put updates an object on the tado° API.
 // If the update is successful and v is a pointer, put will decode the response
 // body into the value pointed to by v. If v is not a pointer the response body

client_test.go

@@ -157,6 +157,80 @@ func TestGet(t *testing.T) {
 	}
 }
 
+func TestPost(t *testing.T) {
+	tests := map[string]struct {
+		url      string
+		mockResp *http.Response
+		mockErr  error
+		wantErr  error
+	}{
+		"Simple": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusNoContent, ""),
+			mockErr:  nil,
+			wantErr:  nil,
+		},
+		"InvalidURL": {
+			url:      "invalid://url%%",
+			mockResp: nil,
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("unable to create http request: parse \"invalid://url%%%%\": invalid URL escape \"%%%%\""),
+		},
+		"HTTPClientError": {
+			url:      "http://example.org",
+			mockResp: nil,
+			mockErr:  fmt.Errorf("http client error"),
+			wantErr:  fmt.Errorf("unable to talk to tado° API: http client error"),
+		},
+		"UnexepctedResponseCode": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusOK, `{"foo": "foo","bar": "bar"}`),
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("unexpected tado° API response status: OK"),
+		},
+		"EmptyErrorList": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusInternalServerError, `{"errors":[]}`),
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("tado° API error: API returned empty error"),
+		},
+		"SingleError": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusInternalServerError, `{"errors":[{"code":"1","title":"One"}]}`),
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("tado° API error: 1: One"),
+		},
+		"MultiError": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusInternalServerError, `{"errors":[{"code":"1","title":"One"},{"code":"2","title":"Two"}]}`),
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("tado° API error: 1: One, 2: Two"),
+		},
+		"UnparseableError": {
+			url:      "http://example.org",
+			mockResp: makeResponse(http.StatusInternalServerError, `{errorjson}`),
+			mockErr:  nil,
+			wantErr:  fmt.Errorf("tado° API error: unable to decode API error: invalid character 'e' looking for beginning of object key string"),
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			client := NewClient("test", "test")
+			client.http = mockHTTPClient{Response: tc.mockResp, Error: tc.mockErr}
+
+			err := client.post(tc.url)
+
+			if tc.wantErr != nil {
+				assert.EqualError(t, err, tc.wantErr.Error())
+			} else {
+				assert.NoError(t, err)
+			}
+
+		})
+	}
+}
+
 func TestPut(t *testing.T) {
 	type foobar struct {
 		Foo string `json:"foo"`

tado.go

@@ -3,7 +3,6 @@ package gotado
 import (
 	"errors"
 	"fmt"
-	"net/http"
 	"strconv"
 )
 
@@ -550,15 +549,7 @@ func DeleteZoneOverlay(client *Client, userHome *UserHome, zone *Zone) error {
 
 // SetWindowOpen marks the window in a zone as open (open window must have been detected before)
 func SetWindowOpen(client *Client, userHome *UserHome, zone *Zone) error {
-	resp, err := client.Request(http.MethodPost, apiURL("homes/%d/zones/%d/state/openWindow/activate", userHome.ID, zone.ID), nil)
-	if err != nil {
-		return err
-	}
-
-	if resp.StatusCode != http.StatusNoContent {
-		return fmt.Errorf("unexpected tado° API response status: %s", resp.Status)
-	}
-	return nil
+	return client.post(apiURL("homes/%d/zones/%d/state/openWindow/activate", userHome.ID, zone.ID))
 }
 
 // SetWindowClosed marks the window in a zone as closed