adapter-patterns

Adapter Implementation Patterns

Reference patterns for implementing API methods in internal/adapters/nylas/.

---

File Structure

internal/adapters/nylas/
├── {resource}.go           # Main implementation
├── {resource}_test.go      # Unit tests
└── mock_{resource}.go      # Mock implementation

---

List Method

// GetResources retrieves resources for a grant.
func (c *HTTPClient) GetResources(ctx context.Context, grantID string, params *domain.ResourceQueryParams) ([]domain.Resource, error) {
    result, err := c.GetResourcesWithCursor(ctx, grantID, params)
    if err != nil {
        return nil, err
    }
    return result.Data, nil
}

// GetResourcesWithCursor retrieves resources with pagination cursor.
func (c *HTTPClient) GetResourcesWithCursor(ctx context.Context, grantID string, params *domain.ResourceQueryParams) (*domain.ResourceListResponse, error) {
    queryURL := fmt.Sprintf("%s/v3/grants/%s/resources", c.baseURL, grantID)

    queryParams := url.Values{}
    if params != nil {
        if params.Limit > 0 {
            queryParams.Set("limit", strconv.Itoa(params.Limit))
        }
        if params.PageToken != "" {
            queryParams.Set("page_token", params.PageToken)
        }
        // Add resource-specific params
    }

    if len(queryParams) > 0 {
        queryURL += "?" + queryParams.Encode()
    }

    req, err := http.NewRequestWithContext(ctx, "GET", queryURL, nil)
    if err != nil {
        return nil, err
    }
    c.setAuthHeader(req)

    resp, err := c.httpClient.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    if resp.StatusCode != http.StatusOK {
        return nil, c.handleErrorResponse(resp)
    }

    var result domain.ResourceListResponse
    if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
        return nil, err
    }
    return &result, nil
}

---

Get Single Method

// GetResource retrieves a single resource by ID.
func (c *HTTPClient) GetResource(ctx context.Context, grantID, resourceID string) (*domain.Resource, error) {
    queryURL := fmt.Sprintf("%s/v3/grants/%s/resources/%s", c.baseURL, grantID, resourceID)

    req, err := http.NewRequestWithContext(ctx, "GET", queryURL, nil)
    if err != nil {
        return nil, err
    }
    c.setAuthHeader(req)

    resp, err := c.httpClient.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    if resp.StatusCode != http.StatusOK {
        return nil, c.handleErrorResponse(resp)
    }

    var result struct {
        Data domain.Resource `json:"data"`
    }
    if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
        return nil, err
    }
    return &result.Data, nil
}