Improve test coverage (#105)

* Add lots of tests

* Move bin logic to lib

* Fix clippy

* Remove testing-plan doc

Author: samshadwell

src/api/handlers.rs

@@ -0,0 +1,109 @@
+//! HTTP API handler for subscription management.
+//!
+//! Framework-agnostic: accepts `ApiRequest`, returns `ApiResponse`.
+//! The Lambda entry point in `src/bin/api.rs` adapts `lambda_http` types to/from
+//! these and calls `handle`.
+
+mod handlers;
+
+use crate::captcha::Captcha;
+use crate::mailer::Mailer;
+use crate::storage::Storage;
+use std::collections::HashMap;
+use std::sync::Arc;
+
+// ============================================================================
+// Request / Response types
+// ============================================================================
+
+pub struct ApiRequest {
+    pub method: String,
+    pub path: String,
+    pub query: HashMap<String, String>,
+    pub body: Option<String>,
+}
+
+pub enum ApiResponse {
+    Html(String),
+    Json { status: u16, body: String },
+    Text { status: u16, body: String },
+    Redirect(String),
+}
+
+impl ApiResponse {
+    pub fn status(&self) -> u16 {
+        match self {
+            Self::Html(_) => 200,
+            Self::Json { status, .. } => *status,
+            Self::Text { status, .. } => *status,
+            Self::Redirect(_) => 303,
+        }
+    }
+
+    pub fn redirect_location(&self) -> Option<&str> {
+        if let Self::Redirect(loc) = self {
+            Some(loc)
+        } else {
+            None
+        }
+    }
+
+    pub fn body_contains(&self, s: &str) -> bool {
+        match self {
+            Self::Html(body) | Self::Json { body, .. } | Self::Text { body, .. } => {
+                body.contains(s)
+            }
+            Self::Redirect(_) => false,
+        }
+    }
+}
+
+// ============================================================================
+// Application state
+// ============================================================================
+
+pub struct AppState<S, M, C> {
+    pub(crate) storage: Arc<S>,
+    pub(crate) mailer: Arc<M>,
+    pub(crate) captcha: C,
+    pub(crate) base_url: String,
+}
+
+impl<S, M, C> AppState<S, M, C> {
+    pub fn new(storage: Arc<S>, mailer: Arc<M>, captcha: C, base_url: String) -> Self {
+        Self {
+            storage,
+            mailer,
+            captcha,
+            base_url,
+        }
+    }
+}
+
+// ============================================================================
+// Dispatch
+// ============================================================================
+
+pub async fn handle<S, M, C>(request: &ApiRequest, state: &Arc<AppState<S, M, C>>) -> ApiResponse
+where
+    S: Storage,
+    M: Mailer,
+    C: Captcha,
+{
+    let token = request.query.get("token").map(|s| s.as_str()).unwrap_or("");
+    let email = request.query.get("email").map(|s| s.as_str()).unwrap_or("");
+    let body = request.body.as_deref().unwrap_or("");
+
+    match (request.method.as_str(), request.path.as_str()) {
+        ("POST", "/api/subscribe") => handlers::subscribe_post(state, body).await,
+        ("GET", "/api/verify") => handlers::verify_get(state, email, token).await,
+        ("GET", "/api/unsubscribe") => handlers::unsubscribe_get(&state.storage, token).await,
+        ("POST", "/api/unsubscribe") => {
+            handlers::unsubscribe_post(&state.storage, token, request.body.as_deref()).await
+        }
+        _ => ApiResponse::Text {
+            status: 404,
+            body: "Not Found".to_string(),
+        },
+    }
+}

src/api/mod.rs

@@ -1,7 +1,7 @@
 use anyhow::{Context, Result};
 use aws_config::BehaviorVersion;
 use email_address::EmailAddress;
-use hndigest::storage_adapter::StorageAdapter;
+use hndigest::storage::{LambdaStorage, Storage};
 use hndigest::strategies::DigestStrategy;
 use hndigest::types::Subscriber;
 use std::env;
@@ -29,7 +29,7 @@ async fn main() -> Result<()> {
     println!("Initializing DynamoDB client...");
     let config = aws_config::load_defaults(BehaviorVersion::latest()).await;
     let dynamodb_client = aws_sdk_dynamodb::Client::new(&config);
-    let storage_adapter = Arc::new(StorageAdapter::new(dynamodb_client, dynamodb_table));
+    let storage_adapter = Arc::new(LambdaStorage::new(dynamodb_client, dynamodb_table));
 
     println!("Creating subscriber for {}", email);
     let subscriber = Subscriber::new(email, strategy);