From f07222179293c1cd90d797d346e46609068d5b66 Mon Sep 17 00:00:00 2001
From: Mathias Lafeldt <mathias.lafeldt@gmail.com>
Date: Fri, 13 Aug 2021 23:07:01 +0200
Subject: [PATCH] Add unit tests

---
 Cargo.lock          | 369 ++++++++++++++++++++++++++++++++++++++++++--
 Cargo.toml          |   3 +
 heartbeat/lambda.rs |  60 ++++++-
 3 files changed, 422 insertions(+), 10 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5fe7ff2..762eb74 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,38 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "anyhow"
+version = "1.0.42"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "595d3cfa7a60d4555cb5067b99f07142a08ea778de5cf993f7b75c7d8fabc486"
+
+[[package]]
+name = "arrayvec"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
+
+[[package]]
+name = "async-channel"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2114d64672151c0c5eaa5e131ec84a74f06e1e559830dabba01ca30605d66319"
+dependencies = [
+ "concurrent-queue",
+ "event-listener",
+ "futures-core",
+]
+
 [[package]]
 name = "async-stream"
 version = "0.3.2"
@@ -23,6 +55,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "async-trait"
+version = "0.1.51"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44318e776df68115a881de9a8fd1b9e53368d7a4a5ce4cc48517da3393233a5e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -64,6 +107,12 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b700ce4376041dcd0a327fd0097c41095743c4c8af8887265942faf1100bd040"
 
+[[package]]
+name = "cache-padded"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "631ae5198c9be5e753e5cc215e1bd73c2b466a3565173db433f52bb9d3e66dba"
+
 [[package]]
 name = "cc"
 version = "1.0.69"
@@ -100,6 +149,26 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "concurrent-queue"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30ed07550be01594c6026cff2a1d7fe9c8f683caa798e12b68694ac9e88286a3"
+dependencies = [
+ "cache-padded",
+]
+
+[[package]]
+name = "config"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19b076e143e1d9538dde65da30f8481c2a6c44040edb8e02b9bf1351edb92ce3"
+dependencies = [
+ "lazy_static",
+ "nom",
+ "serde",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.1"
@@ -116,6 +185,40 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea221b5284a47e40033bf9b66f35f984ec0ea2931eb03505246cd27a963f981b"
 
+[[package]]
+name = "crossbeam-queue"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b10ddc024425c88c2ad148c1b0fd53f4c6d38db9697c9f1588381212fa657c9"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d82cfc11ce7f2c3faef78d8a684447b40d503d9681acebed6cb728d45940c4db"
+dependencies = [
+ "cfg-if",
+ "lazy_static",
+]
+
+[[package]]
+name = "deadpool"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d126179d86aee4556e54f5f3c6bf6d9884e7cc52cef82f77ee6f90a7747616d"
+dependencies = [
+ "async-trait",
+ "config",
+ "crossbeam-queue",
+ "num_cpus",
+ "serde",
+ "tokio",
+]
+
 [[package]]
 name = "dilbert-feed"
 version = "0.1.0"
@@ -128,6 +231,7 @@ dependencies = [
  "serde_json",
  "simple_logger",
  "tokio",
+ "wiremock",
 ]
 
 [[package]]
@@ -139,6 +243,21 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "event-listener"
+version = "2.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7531096570974c3a9dcf9e4b8e1cede1ec26cf5046219fb3b9d897503b9be59"
+
+[[package]]
+name = "fastrand"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b394ed3d285a429378d3b384b9eb1285267e7df4b166df24b7a6939a04dc392e"
+dependencies = [
+ "instant",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -218,6 +337,21 @@ version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b0e06c393068f3a6ef246c75cdca793d6a46347e75286933e5e75fd2fd11582"
 
+[[package]]
+name = "futures-lite"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7694489acd39452c77daa48516b894c153f192c3578d5a839b62c58099fcbf48"
+dependencies = [
+ "fastrand",
+ "futures-core",
+ "futures-io",
+ "memchr",
+ "parking",
+ "pin-project-lite",
+ "waker-fn",
+]
+
 [[package]]
 name = "futures-macro"
 version = "0.3.16"
@@ -243,6 +377,12 @@ version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbe54a98670017f3be909561f6ad13e810d9a51f3f061b902062ca3da80799f2"
 
+[[package]]
+name = "futures-timer"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e64b03909df88034c26dc1547e8970b91f98bdb65165d6a4e9110d94263dbb2c"
+
 [[package]]
 name = "futures-util"
 version = "0.3.16"
@@ -264,6 +404,17 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.3"
@@ -272,7 +423,7 @@ checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.10.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -331,6 +482,27 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "http-types"
+version = "2.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e9b187a72d63adbfba487f48095306ac823049cb504ee195541e91c7775f5ad"
+dependencies = [
+ "anyhow",
+ "async-channel",
+ "base64",
+ "futures-lite",
+ "http",
+ "infer",
+ "pin-project-lite",
+ "rand 0.7.3",
+ "serde",
+ "serde_json",
+ "serde_qs",
+ "serde_urlencoded",
+ "url",
+]
+
 [[package]]
 name = "httparse"
 version = "1.4.1"
@@ -401,6 +573,21 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "infer"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64e9829a50b42bb782c1df523f78d332fe371b10c661e78b7a3c34b0198e9fac"
+
+[[package]]
+name = "instant"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bee0328b1209d157ef001c94dd85b4f8f64139adb0eac2659f4b08382b2f474d"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "ipnet"
 version = "2.3.1"
@@ -448,6 +635,19 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "lexical-core"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6607c62aa161d23d17a9072cc5da0be67cdfc89d3afb1e8d9c842bebc2525ffe"
+dependencies = [
+ "arrayvec",
+ "bitflags",
+ "cfg-if",
+ "ryu",
+ "static_assertions",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.98"
@@ -521,6 +721,17 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "nom"
+version = "5.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffb4262d26ed83a1c0a33a38fe2bb15797329c85770da05e6b828ddb782627af"
+dependencies = [
+ "lexical-core",
+ "memchr",
+ "version_check",
+]
+
 [[package]]
 name = "ntapi"
 version = "0.3.6"
@@ -608,6 +819,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "parking"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "427c3892f9e783d91cc128285287e70a59e206ca452770ece88a76f7a3eddd72"
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -668,6 +885,19 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom 0.1.16",
+ "libc",
+ "rand_chacha 0.2.2",
+ "rand_core 0.5.1",
+ "rand_hc 0.2.0",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.4"
@@ -675,9 +905,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2e7573632e6454cf6b99d7aac4ccca54be06da05aca2ef7423d22d27d4d4bcd8"
 dependencies = [
  "libc",
- "rand_chacha",
- "rand_core",
- "rand_hc",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.3",
+ "rand_hc 0.3.1",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -687,7 +927,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.3",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom 0.1.16",
 ]
 
 [[package]]
@@ -696,7 +945,16 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.3",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -705,7 +963,7 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d51e9f596de227fda2ea6c84607f5558e196eeaf43c986b724ba4fb8fdf497e7"
 dependencies = [
- "rand_core",
+ "rand_core 0.6.3",
 ]
 
 [[package]]
@@ -717,6 +975,23 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"
@@ -830,6 +1105,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_qs"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8a72808528a89fa9eca23bbb6a1eb92cb639b881357269b6510f11e50c0f8a9"
+dependencies = [
+ "percent-encoding",
+ "serde",
+ "thiserror",
+]
+
 [[package]]
 name = "serde_urlencoded"
 version = "0.7.0"
@@ -880,6 +1166,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "static_assertions"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
+
 [[package]]
 name = "syn"
 version = "1.0.74"
@@ -899,12 +1191,32 @@ checksum = "dac1c663cfc93810f88aed9b8941d48cabf856a1b111c29a40439018d870eb22"
 dependencies = [
  "cfg-if",
  "libc",
- "rand",
+ "rand 0.8.4",
  "redox_syscall",
  "remove_dir_all",
  "winapi",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93119e4feac1cbe6c798c34d3a53ea0026b0b1de6a120deef895137c0529bfe2"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "060d69a0afe7796bf42e9e2ff91f5ee691fb15c53d38b4b62a9a53eb23164745"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.1.3"
@@ -921,7 +1233,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6db9e6914ab8b1ae1c260a4ae7a49b6c5611b40328a735b21862567685e73255"
 dependencies = [
  "libc",
- "wasi",
+ "wasi 0.10.0+wasi-snapshot-preview1",
  "winapi",
 ]
 
@@ -1103,6 +1415,7 @@ dependencies = [
  "idna",
  "matches",
  "percent-encoding",
+ "serde",
 ]
 
 [[package]]
@@ -1111,6 +1424,18 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
 
+[[package]]
+name = "version_check"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
+
+[[package]]
+name = "waker-fn"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d5b2c62b4012a3e1eca5a7e077d13b3bf498c4073e33ccd58626607748ceeca"
+
 [[package]]
 name = "want"
 version = "0.3.0"
@@ -1121,6 +1446,12 @@ dependencies = [
  "try-lock",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wasi"
 version = "0.10.0+wasi-snapshot-preview1"
@@ -1235,3 +1566,23 @@ checksum = "0120db82e8a1e0b9fb3345a539c478767c0048d842860994d96113d5b667bd69"
 dependencies = [
  "winapi",
 ]
+
+[[package]]
+name = "wiremock"
+version = "0.5.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d98dba85d7b65ebd45e9a48315bae224bd3616f157025d3ccdaa207dcecee1b"
+dependencies = [
+ "async-trait",
+ "deadpool",
+ "futures",
+ "futures-timer",
+ "http-types",
+ "hyper",
+ "log",
+ "once_cell",
+ "regex",
+ "serde",
+ "serde_json",
+ "tokio",
+]
diff --git a/Cargo.toml b/Cargo.toml
index f6eb777..c9bfdb3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,3 +21,6 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 simple_logger = "1.13"
 tokio = "1.9"
+
+[dev-dependencies]
+wiremock = "0.5"
diff --git a/heartbeat/lambda.rs b/heartbeat/lambda.rs
index 2902490..7bee173 100644
--- a/heartbeat/lambda.rs
+++ b/heartbeat/lambda.rs
@@ -14,7 +14,7 @@ struct Input {
     extra: HashMap<String, Value>,
 }
 
-#[derive(Serialize)]
+#[derive(Serialize, PartialEq, Debug)]
 struct Output {
     endpoint: String,
     status: u16,
@@ -52,3 +52,61 @@ async fn handler(input: Input, _: Context) -> Result<Output, Error> {
         status: resp.status().as_u16(),
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use wiremock::matchers::method;
+    use wiremock::{Mock, MockServer, ResponseTemplate};
+
+    #[tokio::test]
+    async fn test_handler_200() {
+        let server = MockServer::start().await;
+
+        Mock::given(method("GET"))
+            .respond_with(ResponseTemplate::new(200))
+            .expect(1)
+            .mount(&server)
+            .await;
+
+        let resp = handler(
+            Input {
+                endpoint: Some(server.uri()),
+                extra: HashMap::new(),
+            },
+            Context::default(),
+        )
+        .await
+        .unwrap();
+
+        assert_eq!(
+            resp,
+            Output {
+                endpoint: server.uri(),
+                status: 200,
+            },
+        );
+    }
+
+    #[tokio::test]
+    #[should_panic(expected = "HTTP status not 2xx: 503 Service Unavailable")]
+    async fn test_handler_503() {
+        let server = MockServer::start().await;
+
+        Mock::given(method("GET"))
+            .respond_with(ResponseTemplate::new(503))
+            .expect(1)
+            .mount(&server)
+            .await;
+
+        handler(
+            Input {
+                endpoint: Some(server.uri()),
+                extra: HashMap::new(),
+            },
+            Context::default(),
+        )
+        .await
+        .unwrap();
+    }
+}