Adds a prepare script to @datadog/browser-rum-react

[arcanis]

Motivation

The standard prepack script is called by Yarn when a repository is installed as a dependency. Its purpose is to let the package describe how its sources should be compiled when yarn pack is called. Since the script was missing, Yarn was packing the original TypeScript source files rather than the JavaScript ones.

Changes

Adds a prepack script that calls npm run build. The reason it's npm run (rather than yarn run, despite the repository being installed with Yarn) is that the build script currently relies on hoisting to have most of its binaries available. Running yarn run won't make those binaries available (because they aren't dependencies of @datadog/browser-rum-react), but npm run (because it just puts as many bins as possible in node_modules/.bin). Since Lerna works, it suggests that they are using npm run even on Yarn-installed projects.

Testing

• Local
• Staging
• Unit
• End to end

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I have gone over the contributing documentation.

[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	161.96 KiB	161.96 KiB	0 B	0.00%	✅
Logs	55.84 KiB	55.84 KiB	0 B	0.00%	✅
Rum Slim	110.80 KiB	110.80 KiB	0 B	0.00%	✅
Worker	25.21 KiB	25.21 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base Average Cpu Time (ms)	Local Average Cpu Time (ms)	𝚫
addglobalcontext	0.002	0.001	-0.000
addaction	0.040	0.039	-0.001
addtiming	0.001	0.001	0.000
adderror	0.040	0.036	-0.005
startstopsessionreplayrecording	1.143	1.063	-0.081
startview	1.082	1.395	0.313
logmessage	0.021	0.022	0.001

🧠 Memory Performance

Action Name	Base Consumption Memory (bytes)	Local Consumption Memory (bytes)	𝚫 (bytes)
addglobalcontext	7.99 KiB	7.38 KiB	-627 B
addaction	39.20 KiB	39.44 KiB	245 B
addtiming	8.07 KiB	7.35 KiB	-735 B
adderror	45.58 KiB	44.03 KiB	-1591 B
startstopsessionreplayrecording	4.47 KiB	4.78 KiB	323 B
startview	420.06 KiB	426.23 KiB	6.17 KiB
logmessage	41.67 KiB	40.43 KiB	-1269 B

🔗 RealWorld