Adds user agent header for requests to Green Web Foundation APIs

the version from package.json is used to inject an environment variable
when esbuild runs, which the running code can read to create the correct
user agent string when making requests.

fixes thegreenwebfoundation#181

.esbuild.browser.js

@@ -1,4 +1,7 @@
+const esbuildCommon = require("./.esbuild.common");
+
 require('esbuild').buildSync({
+  ...esbuildCommon,
   entryPoints: ['src/index.js'],
   outdir: 'dist/iife',
   globalName: 'co2',

.esbuild.common.js

@@ -0,0 +1,7 @@
+const CO2JS_VERSION = require("./package.json").version;
+
+module.exports = {
+  define: {
+    "process.env.CO2JS_VERSION": JSON.stringify(CO2JS_VERSION),
+  },
+};

.esbuild.esm.js

@@ -3,7 +3,8 @@ const esbuild = require('esbuild')
 // For this build however we need to filter out some extra files
 // that are used for nodejs, but not in browsers, so we use the
 // library directly instead of using `esbuild-plugin-glob` as a plugin
-const glob = require('tiny-glob');
+const glob = require('tiny-glob')
+const esbuildCommon = require('./.esbuild.common')
 
 async function main() {
   const results = await glob('src/**/!(*.test.js|test-constants.js|!(*.js))')
@@ -12,6 +13,7 @@ async function main() {
   const justBrowserCompatibleFiles = results.filter(filepath => !filepath.endsWith('node.js'))
 
   esbuild.build({
+    ...esbuildCommon,
     entryPoints: justBrowserCompatibleFiles,
     bundle: false,
     minify: false,

.esbuild.node.js

@@ -1,7 +1,9 @@
 const { globPlugin } = require('esbuild-plugin-glob');
+const esbuildCommon = require('./.esbuild.common');
 
 function main() {
   require('esbuild').build({
+    ...esbuildCommon,
     entryPoints: ['src/**/!(*.test.js|test-constants.js|!(*.js))'],
     bundle: false,
     minify: false,

src/helpers/index.js

@@ -172,4 +172,13 @@ function parseOptions(options) {
   return adjustments;
 }
 
-export { formatNumber, parseOptions };
+/**
+ * Returns an object containing all the HTTP headers to use when making a request to the Green Web Foundation API.
+ *
+ * @returns {import('http').OutgoingHttpHeaders}
+ */
+function getApiRequestHeaders() {
+  return { "user-agent": `co2js/${process.env.CO2JS_VERSION}` };
+}
+
+export { formatNumber, parseOptions, getApiRequestHeaders };

src/hosting-api.js

@@ -1,5 +1,7 @@
 "use strict";
 
+import { getApiRequestHeaders } from "./helpers";
+
 /**
  * Check if a string or array of domains has been provided
  * @param {string|array} domain - The domain to check, or an array of domains to be checked.
@@ -21,7 +23,10 @@ function check(domain) {
  */
 async function checkAgainstAPI(domain) {
   const req = await fetch(
-    `https://api.thegreenwebfoundation.org/greencheck/${domain}`
+    `https://api.thegreenwebfoundation.org/greencheck/${domain}`,
+    {
+      headers: getApiRequestHeaders(),
+    }
   );
   const res = await req.json();
   return res.green;
@@ -38,7 +43,9 @@ async function checkDomainsAgainstAPI(domains) {
     const apiPath = "https://api.thegreenwebfoundation.org/v2/greencheckmulti";
     const domainsString = JSON.stringify(domains);
 
-    const req = await fetch(`${apiPath}/${domainsString}`);
+    const req = await fetch(`${apiPath}/${domainsString}`, {
+      headers: getApiRequestHeaders(),
+    });
 
     const allGreenCheckResults = await req.json();
 

src/hosting-api.test.js

@@ -3,6 +3,9 @@
 import hosting from "./hosting-node.js";
 import nock from "nock";
 /* eslint-disable jest/no-disabled-tests */
+
+process.env.CO2JS_VERSION = "1.2.34";
+
 describe("hostingAPI", () => {
   describe("checking a single domain with #check", () => {
     it.skip("using the API", async () => {
@@ -15,6 +18,20 @@ describe("hostingAPI", () => {
       const res = await hosting.check("google.com");
       expect(res).toEqual(true);
     });
+    it("sets the correct user agent header", async () => {
+      let userAgent;
+      const scope = nock("https://api.thegreenwebfoundation.org/")
+        .get("/greencheck/google.com")
+        .reply(200, function () {
+          userAgent = this.req.headers["user-agent"];
+          return {
+            url: "google.com",
+            green: true,
+          };
+        });
+      const res = await hosting.check("google.com");
+      expect(userAgent).toEqual("co2js/1.2.34");
+    });
   });
   describe("implicitly checking multiple domains with #check", () => {
     it.skip("using the API", async () => {

src/hosting-node.js

@@ -11,6 +11,7 @@ This lets us keep the total library small, and dependencies minimal.
 import https from "https";
 
 import hostingJSON from "./hosting-json.node.js";
+import { getApiRequestHeaders } from "./helpers/index.js";
 
 /**
  * Accept a url and perform an http request, returning the body
@@ -22,22 +23,26 @@ import hostingJSON from "./hosting-json.node.js";
 async function getBody(url) {
   return new Promise(function (resolve, reject) {
     // Do async job
-    const req = https.get(url, function (res) {
-      if (res.statusCode < 200 || res.statusCode >= 300) {
-        return reject(
-          new Error(
-            `Could not get info from: ${url}. Status Code: ${res.statusCode}`
-          )
-        );
-      }
-      const data = [];
+    const req = https.get(
+      url,
+      { headers: getApiRequestHeaders() },
+      function (res) {
+        if (res.statusCode < 200 || res.statusCode >= 300) {
+          return reject(
+            new Error(
+              `Could not get info from: ${url}. Status Code: ${res.statusCode}`
+            )
+          );
+        }
+        const data = [];
 
-      res.on("data", (chunk) => {
-        data.push(chunk);
-      });
+        res.on("data", (chunk) => {
+          data.push(chunk);
+        });
 
-      res.on("end", () => resolve(Buffer.concat(data).toString()));
-    });
+        res.on("end", () => resolve(Buffer.concat(data).toString()));
+      }
+    );
     req.end();
   });
 }

src/hosting.test.js

@@ -1,12 +1,15 @@
 "use strict";
 
 import fs from "fs";
+import https from "https";
 import path from "path";
 
 import pagexray from "pagexray";
 
 import hosting from "./hosting-node.js";
 
+process.env.CO2JS_VERSION = "1.2.34";
+
 const jsonPath = path.resolve(
   __dirname,
   "..",
@@ -17,13 +20,18 @@ const jsonPath = path.resolve(
 
 describe("hosting", () => {
   let har;
+  let httpsGetSpy;
   beforeEach(() => {
     har = JSON.parse(
       fs.readFileSync(
         path.resolve(__dirname, "../data/fixtures/tgwf.har"),
         "utf8"
       )
     );
+    httpsGetSpy = jest.spyOn(https, "get");
+  });
+  afterEach(() => {
+    jest.restoreAllMocks();
   });
   describe("checking all domains on a page object with #checkPage", () => {
     it("returns a list of green domains, when passed a page object", async () => {
@@ -57,6 +65,15 @@ describe("hosting", () => {
       const res = await hosting.check("google.com");
       expect(res).toEqual(true);
     });
+    it("sets the correct user agent header", async () => {
+      await hosting.check("google.com");
+      expect(httpsGetSpy).toHaveBeenCalledTimes(1);
+      expect(httpsGetSpy).toHaveBeenLastCalledWith(
+        expect.any(String),
+        expect.objectContaining({ headers: { "user-agent": "co2js/1.2.34" } }),
+        expect.any(Function)
+      );
+    });
   });
   describe("checking multiple domains with #check", () => {
     it("Use the API", async () => {