feat: add structured pino logging and validated log-level config

test/config.test.js

@@ -7,11 +7,13 @@ test("config uses defaults when env is missing", () => {
   const previous = {
     PORT: process.env.PORT,
     STATE_FILE_PATH: process.env.STATE_FILE_PATH,
+    LOG_LEVEL: process.env.LOG_LEVEL,
     WEBHOOK_RPM: process.env.WEBHOOK_RPM,
   };
 
   delete process.env.PORT;
   delete process.env.STATE_FILE_PATH;
+  delete process.env.LOG_LEVEL;
   delete process.env.WEBHOOK_RPM;
 
   delete require.cache[require.resolve("../src/config")];
@@ -19,6 +21,7 @@ test("config uses defaults when env is missing", () => {
 
   assert.equal(config.port, 3000);
   assert.equal(config.stateFilePath, "./data/state.json");
+  assert.equal(config.logLevel, "info");
   assert.equal(config.rateLimits.webhookPerMinute, 120);
 
   if (previous.PORT === undefined) {
@@ -33,6 +36,12 @@ test("config uses defaults when env is missing", () => {
     process.env.STATE_FILE_PATH = previous.STATE_FILE_PATH;
   }
 
+  if (previous.LOG_LEVEL === undefined) {
+    delete process.env.LOG_LEVEL;
+  } else {
+    process.env.LOG_LEVEL = previous.LOG_LEVEL;
+  }
+
   if (previous.WEBHOOK_RPM === undefined) {
     delete process.env.WEBHOOK_RPM;
   } else {
@@ -44,11 +53,13 @@ test("config reads state path and numeric env overrides", () => {
   const previous = {
     PORT: process.env.PORT,
     STATE_FILE_PATH: process.env.STATE_FILE_PATH,
+    LOG_LEVEL: process.env.LOG_LEVEL,
     WEBHOOK_RPM: process.env.WEBHOOK_RPM,
   };
 
   process.env.PORT = "8080";
   process.env.STATE_FILE_PATH = "/data/prod-state.json";
+  process.env.LOG_LEVEL = "debug";
   process.env.WEBHOOK_RPM = "77";
 
   delete require.cache[require.resolve("../src/config")];
@@ -56,6 +67,7 @@ test("config reads state path and numeric env overrides", () => {
 
   assert.equal(config.port, 8080);
   assert.equal(config.stateFilePath, "/data/prod-state.json");
+  assert.equal(config.logLevel, "debug");
   assert.equal(config.rateLimits.webhookPerMinute, 77);
 
   if (previous.PORT === undefined) {
@@ -69,6 +81,11 @@ test("config reads state path and numeric env overrides", () => {
   } else {
     process.env.STATE_FILE_PATH = previous.STATE_FILE_PATH;
   }
+  if (previous.LOG_LEVEL === undefined) {
+    delete process.env.LOG_LEVEL;
+  } else {
+    process.env.LOG_LEVEL = previous.LOG_LEVEL;
+  }
   if (previous.WEBHOOK_RPM === undefined) {
     delete process.env.WEBHOOK_RPM;
   } else {

test/logger.test.js

@@ -0,0 +1,12 @@
+"use strict";
+
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const { createLogger } = require("../src/lib/logger");
+
+test("createLogger returns pino-compatible logger", () => {
+  const logger = createLogger({ level: "debug", name: "test" });
+  assert.equal(typeof logger.info, "function");
+  assert.equal(typeof logger.error, "function");
+  assert.equal(logger.level, "debug");
+});