rework error messages including tests

samplers/aws/xray/internal/client.go

@@ -130,22 +130,22 @@ func (c *xrayClient) getSamplingRules(ctx context.Context) (*getSamplingRulesOut
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.samplingRulesURL, body)
 	if err != nil {
-		return nil, fmt.Errorf("xray client: failed to create http request: %w", err)
+		return nil, fmt.Errorf("unable to retrieve sampling rules, error on http request: %w", err)
 	}
 
 	output, err := c.httpClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("xray client: unable to retrieve sampling settings: %w", err)
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling rules, error on http request:  %w", err)
 	}
 	defer func() { _ = output.Body.Close() }()
 
 	if output.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("xray client: unable to retrieve sampling settings, expected response status code 200, got: %d", output.StatusCode)
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling rules, expected response status code 200, got: %d", output.StatusCode)
 	}
 
 	var samplingRulesOutput *getSamplingRulesOutput
 	if err := json.NewDecoder(output.Body).Decode(&samplingRulesOutput); err != nil {
-		return nil, fmt.Errorf("xray client: unable to unmarshal the response body: %w", err)
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling rules, unable to unmarshal the response body: %w", err)
 	}
 
 	return samplingRulesOutput, nil
@@ -170,7 +170,7 @@ func (c *xrayClient) getSamplingTargets(ctx context.Context, s []*samplingStatis
 
 	output, err := c.httpClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("xray client: unable to retrieve sampling settings: %w", err)
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling targets, error on http request: %w", err)
 	}
 	defer func() { _ = output.Body.Close() }()
 
@@ -180,7 +180,7 @@ func (c *xrayClient) getSamplingTargets(ctx context.Context, s []*samplingStatis
 
 	var samplingTargetsOutput *getSamplingTargetsOutput
 	if err := json.NewDecoder(output.Body).Decode(&samplingTargetsOutput); err != nil {
-		return nil, fmt.Errorf("xray client: unable to unmarshal the response body: %w", err)
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling targets, unable to unmarshal the response body: %w", err)
 	}
 
 	return samplingTargetsOutput, nil

samplers/aws/xray/internal/client_test.go

@@ -254,10 +254,12 @@ func TestEndpointIsNotReachable(t *testing.T) {
 
 	actualRules, err := client.getSamplingRules(context.Background())
 	assert.Error(t, err)
+	assert.ErrorContains(t, err, "xray client: unable to retrieve sampling rules, error on http request: ")
 	assert.Nil(t, actualRules)
 
 	actualTargets, err := client.getSamplingTargets(context.Background(), nil)
 	assert.Error(t, err)
+	assert.ErrorContains(t, err, "xray client: unable to retrieve sampling targets, error on http request: ")
 	assert.Nil(t, actualTargets)
 }
 
@@ -266,7 +268,7 @@ func TestRespondsWithErrorStatusCode(t *testing.T) {
 
 	actualRules, err := client.getSamplingRules(context.Background())
 	assert.Error(t, err)
-	assert.EqualError(t, err, fmt.Sprintf("xray client: unable to retrieve sampling settings, expected response status code 200, got: %d", http.StatusForbidden))
+	assert.EqualError(t, err, fmt.Sprintf("xray client: unable to retrieve sampling rules, expected response status code 200, got: %d", http.StatusForbidden))
 	assert.Nil(t, actualRules)
 
 	actualTargets, err := client.getSamplingTargets(context.Background(), nil)
@@ -297,12 +299,12 @@ func TestInvalidResponseBody(t *testing.T) {
 
 			assert.Error(t, err)
 			assert.Nil(t, actualRules)
-			assert.ErrorContains(t, err, "xray client: unable to unmarshal the response body:"+scenario.response)
+			assert.ErrorContains(t, err, "xray client: unable to retrieve sampling rules, unable to unmarshal the response body:"+scenario.response)
 
 			actualTargets, err := client.getSamplingTargets(context.TODO(), nil)
 			assert.Error(t, err)
 			assert.Nil(t, actualTargets)
-			assert.ErrorContains(t, err, "xray client: unable to unmarshal the response body: "+scenario.response)
+			assert.ErrorContains(t, err, "xray client: unable to retrieve sampling targets, unable to unmarshal the response body: "+scenario.response)
 		})
 	}
 }