super simple serverless hit counter for fun (#410)

functions/hits.js

@@ -0,0 +1,74 @@
+const faunadb = require("faunadb"),
+  q = faunadb.query;
+const numeral = require("numeral");
+const pluralize = require("pluralize");
+require("dotenv").config();
+
+// .....??????
+// https://github.com/netlify/netlify-lambda/issues/201
+require("encoding");
+
+exports.handler = async (event, context) => {
+  const { slug } = event.queryStringParameters;
+  const client = new faunadb.Client({
+    secret: process.env.FAUNADB_SERVER_SECRET,
+  });
+
+  // some rudimentary error handling
+  if (!slug || slug === "/") {
+    return {
+      statusCode: 400,
+      body: JSON.stringify({
+        message: "Page slug required.",
+      }),
+    };
+  }
+
+  const result = await client.query(
+    q.Let(
+      {
+        match: q.Match(q.Index("hits_by_slug"), slug),
+      },
+      q.If(
+        q.Exists(q.Var("match")),
+        q.Let(
+          {
+            ref: q.Select("ref", q.Get(q.Var("match"))),
+            hits: q.ToInteger(q.Select("hits", q.Select("data", q.Get(q.Var("match"))))),
+          },
+          q.Update(q.Var("ref"), {
+            data: {
+              hits: q.Add(q.Var("hits"), 1),
+            },
+          })
+        ),
+        q.Create(q.Collection("hits"), {
+          data: {
+            slug: slug,
+            hits: 1,
+          },
+        })
+      )
+    )
+  );
+
+  client.close();
+
+  const hits = result.data.hits;
+
+  // send client the new hit count
+  return {
+    statusCode: 200,
+    headers: {
+      "Cache-Control": "private, no-cache, no-store, must-revalidate",
+      Expires: "0",
+      Pragma: "no-cache",
+    },
+    body: JSON.stringify({
+      slug: slug,
+      hits: hits,
+      pretty_hits: numeral(hits).format("0,0"),
+      pretty_unit: pluralize("hit", hits),
+    }),
+  };
+};