08. Pagespeed Insights (Optional)
Pagespeed Insights (Optional)
Question:
Google's PageSpeed Insights (PSI) scores websites on their speed. A perfect score is 100 and the worst score is 0. Alongside the score, PSI provides relevant advice for improvements.
By integrating an automated PSI score into a suite of front-end unit tests, you can periodically check a website's overall speed.
Let's assume you're building the front-end testing framework and you make a call to the PSI API. You receive the JSON below as a response.
Create a totalBytes(psiResults) function that iterates through pageStats in the psiResults object and returns the total number of bytes to load the website.
Then, create a ruleList(psiResults) function that iterates through the localizedRuleNames in ruleResults and returns an array of their strings.
var psiResults;
psiResults = {
"kind": "pagespeedonline#result",
"id": "/speed/pagespeed",
"responseCode": 200,
"title": "PageSpeed Home",
"score": 90,
"pageStats": {
"numberResources": 22,
"numberHosts": 7,
"totalRequestBytes": "2761",
"numberStaticResources": 16,
"htmlResponseBytes": "91981",
"cssResponseBytes": "37728",
"imageResponseBytes": "13909",
"javascriptResponseBytes": "247214",
"otherResponseBytes": "8804",
"numberJsResources": 6,
"numberCssResources": 2
},
"formattedResults": {
"locale": "en_US",
"ruleResults": {
"AvoidBadRequests": {
"localizedRuleName": "Avoid bad requests",
"ruleImpact": 0.0
},
...
"MinifyJavaScript": {
"localizedRuleName": "Minify JavaScript",
"ruleImpact": 0.1417,
"urlBlocks": [
{
"header": {
"format": "Minifying the following JavaScript resources could reduce their size by $1 ($2% reduction).",
"args": [
{
"type": "BYTES",
"value": "1.3KiB"
},
{
"type": "INT_LITERAL",
"value": "0"
}
]
},
"urls": [
{
"result": {
"format": "Minifying $1 could save $2 ($3% reduction).",
"args": [
{
"type": "URL",
"value": "http://code.google.com/js/codesite_tail.pack.04102009.js"
},
{
"type": "BYTES",
"value": "717B"
},
{
"type": "INT_LITERAL",
"value": "1"
}
]
}
},
...
{
"result": {
"format": "Minifying $1 could save $2 ($3% reduction).",
"args": [
{
"type": "URL",
"value": "http://www.gmodules.com/ig/proxy?url\u003dhttp%3A%2F%2Fjqueryjs.googlecode.com%2Ffiles%2Fjquery-1.2.6.min.js"
},
{
"type": "BYTES",
"value": "258B"
},
{
"type": "INT_LITERAL",
"value": "0"
}
]
}
}
]
}
]
},
...
"SpriteImages": {
"localizedRuleName": "Combine images into CSS sprites",
"ruleImpact": 0.0
}
}
},
"version": {
"major": 1,
"minor": 11
}
}
See the example here.
Start Quiz:
// Iterate through the localizedRuleNames in ruleResults and
// return an array of their strings.
function ruleList(results) {
// Your code goes here!
}
// Iterate through pageStats in the psiResults object and
// return the total number of bytes to load the website.
function totalBytes(results) {
// Your code goes here!
}
// Below, you'll find a sample PS Insights JSON
// and two console.log statements to help you test your code!
psinsights = {
"kind": "pagespeedonline#result",
"id": "/speed/pagespeed",
"responseCode": 200,
"title": "PageSpeed Home",
"score": 90,
"pageStats": {
"numberResources": 22,
"numberHosts": 7,
"totalRequestBytes": "2761",
"numberStaticResources": 16,
"htmlResponseBytes": "91981",
"cssResponseBytes": "37728",
"imageResponseBytes": "13909",
"javascriptResponseBytes": "247214",
"otherResponseBytes": "8804",
"numberJsResources": 6,
"numberCssResources": 2
},
"formattedResults": {
"locale": "en_US",
"ruleResults": {
"AvoidBadRequests": {
"localizedRuleName": "Avoid bad requests",
"ruleImpact": 0.0
},
"MinifyJavaScript": {
"localizedRuleName": "Minify JavaScript",
"ruleImpact": 0.1417,
"urlBlocks": [
{
"header": {
"format": "Minifying the following JavaScript resources could reduce their size by $1 ($2% reduction).",
"args": [
{
"type": "BYTES",
"value": "1.3KiB"
},
{
"type": "INT_LITERAL",
"value": "0"
}
]
},
"urls": [
{
"result": {
"format": "Minifying $1 could save $2 ($3% reduction).",
"args": [
{
"type": "URL",
"value": "http://code.google.com/js/codesite_tail.pack.04102009.js"
},
{
"type": "BYTES",
"value": "717B"
},
{
"type": "INT_LITERAL",
"value": "1"
}
]
}
},
{
"result": {
"format": "Minifying $1 could save $2 ($3% reduction).",
"args": [
{
"type": "URL",
"value": "http://www.gmodules.com/ig/proxy?url\u003dhttp%3A%2F%2Fjqueryjs.googlecode.com%2Ffiles%2Fjquery-1.2.6.min.js"
},
{
"type": "BYTES",
"value": "258B"
},
{
"type": "INT_LITERAL",
"value": "0"
}
]
}
}
]
}
]
},
"SpriteImages": {
"localizedRuleName": "Combine images into CSS sprites",
"ruleImpact": 0.0
}
}
},
"version": {
"major": 1,
"minor": 11
}
};
// Try logging the outputs below to test your code!
console.log(ruleList(psinsights));
console.log(totalBytes(psinsights));