I've seen a lot of tutorials and questions asking how to do DI in .NET for Azure Functions, but none for JavaScript or TypeScript.
How would one go about providing different implementations to Azure Functions?
You can check for multiple blogs where we can understand about DI in JavaScript as DeepDave suggested.
You can refer to this GIT blog where we can find the project about Injectable Type script azure functions. Below is the sample constructor on TypeScript based:
constructor(@inject(contracts.contractSymbols.ICognitiveService) cognitiveService:contracts.ICognitiveService) {
super();
this._cognitiveService = cognitiveService;
}