chore(webpage-impact): introduce config option for reload ratio compu…

…tation

Until now the reload ratio was computed if no dataReloadRatio is provided in
the inputs. That seemed like a reasonable default but it is also too implicit.

Introduce a config option and only compute it if the option is provided.

Signed-off-by: alexzurbonsen <[email protected]>

example-manifests/measure-webpage.yml

@@ -12,8 +12,9 @@ initialize:
       method: WebpageImpact
       path: '@tngtech/if-webpage-plugins'
       config:
-        scrollToBottom: true
         url: https://www.tngtech.com
+        scrollToBottom: true
+        computeReloadRati: true
     'co2js':
       method: Co2js
       path: '@tngtech/if-webpage-plugins'

src/__tests__/unit/lib/webpage-impact/index.test.ts

@@ -91,7 +91,7 @@ describe('lib/webpage-impact', () => {
         jest.spyOn(Date, 'now').mockImplementation(() => mockTimestamp);
 
         const webpageImpact = WebpageImpact(
-          {url: 'http://localhost:3000'},
+          {url: 'http://localhost:3000', computeReloadRatio: true},
           {},
           {}
         );

src/lib/webpage-impact/README.md

@@ -16,6 +16,7 @@ The `WebpageImpact` plugin measures the weight of a webpage in bytes and the wei
 
 The follwing config parameters are optional:
 
+- `computeReloadRatio`: If true, a heuristic value for the `dataReloadRatio` is computed, which can be used as input for the co2js plugin. Any value for the `dataReloadRatio` that is provided as input will be overwritten. The data reload ratio expresses how much data has to be reloaded if the web page is visited a second time.
 - `mobileDevice:`: You can pick a mobile device to emulate. Must be one of puppeteer's known devices: https://pptr.dev/api/puppeteer.knowndevices
 - `emulateNetworkConditions`: You can pick one of puppeteer's predefined network conditions: https://pptr.dev/api/puppeteer.predefinednetworkconditions
 - `scrollToBottom`: If true, emulates a user scrolling to the bottom of the page (which loads all content that isn't loaded on initial load). If false, the page is not scrolled. Default: false.
@@ -28,8 +29,7 @@ The follwing config parameters are optional:
 
 - `network/data/bytes`: page weight in bytes
 - `network/data/resources/bytes`: resource weights by category in bytes
-- `dataReloadRatio`: an estimate of the percentage of data that is downloaded by return visitors (can be fed into the CO2.JS plugin)
-  if `options.dataReloadRatio` is already provided as an input, the plugin won't calculate it
+- `dataReloadRatio`: If `computeReloadRatio` is true: estimate of the amount of data that is reloaded on return visits (Can be fed into the co2js plugin.)
 - `timestamp`: set to the time of the plugin execution
 - `duration`: set to 0 (because the request time does not seem of particular interest here to the author)
 
@@ -72,6 +72,7 @@ initialize:
       path: '@tngtech/if-webpage-plugins'
       config:
         url: 'https://tngtech.com'
+        computeReloadRatio: true
 tree:
   children:
     child:

src/lib/webpage-impact/index.ts

@@ -100,14 +100,8 @@ export const WebpageImpact = PluginFactory({
       inputs.map(async input => {
         const startTime = Date.now();
 
-        const computeReloadRatio = !input?.options?.dataReloadRatio;
-
         const {pageWeight, resourceTypeWeights, dataReloadRatio} =
-          await measurePageImpactMetrics(
-            config.url,
-            computeReloadRatio,
-            config
-          );
+          await measurePageImpactMetrics(config.url, config);
 
         const durationInSeconds = (Date.now() - startTime) / 1000;
 
@@ -118,7 +112,7 @@ export const WebpageImpact = PluginFactory({
           url: config.url,
           'network/data/bytes': pageWeight,
           'network/data/resources/bytes': resourceTypeWeights,
-          ...(dataReloadRatio
+          ...(config.computeReloadRatio && dataReloadRatio
             ? {
                 options: {
                   ...input.options,
@@ -135,7 +129,6 @@ export const WebpageImpact = PluginFactory({
 const WebpageImpactUtils = () => {
   const measurePageImpactMetrics = async (
     url: string,
-    computeReloadRatio: boolean,
     config?: ConfigParams
   ) => {
     const requestHandler = (interceptedRequest: HTTPRequest) => {
@@ -186,7 +179,7 @@ const WebpageImpactUtils = () => {
         });
 
         let reloadedResources: Resource[] | undefined;
-        if (computeReloadRatio) {
+        if (config?.computeReloadRatio) {
           reloadedResources = await loadPageResources(page, url, {
             reload: true,
             cacheEnabled: true,
@@ -377,6 +370,7 @@ const WebpageImpactUtils = () => {
     }
 
     const optionalConfigs = z.object({
+      computeReloadRatio: z.boolean().optional(),
       timeout: z.number().gte(0).optional(),
       mobileDevice: z.string().optional(),
       emulateNetworkConditions: z.string().optional(),
@@ -390,11 +384,6 @@ const WebpageImpactUtils = () => {
             .optional(),
         })
         .optional(),
-      options: z
-        .object({
-          dataReloadRatio: z.number().optional(),
-        })
-        .optional(),
     });
 
     const configSchema = z