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1JavaScript: A High-Level Programming Language
2JavaScript's Origins and Purpose
3JavaScript vs ECMAScript
4JavaScript in the Browser
5JavaScript Beyond the Browser
6JavaScript's Key Characteristics
7The JavaScript Ecosystem
8Why Learn JavaScript in 2024+
9What is a JavaScript Engine?
10V8: Chrome and Node.js
11SpiderMonkey: Firefox's Engine
12JavaScriptCore: Safari's Engine
13Parsing and the Abstract Syntax Tree
14Interpretation vs Compilation
15Just-In-Time (JIT) Compilation
16What is a Runtime?
17Browser Runtime: DOM and Web APIs
18Node.js Runtime: Server-Side JavaScript
19Deno and Bun: Alternative Runtimes
20Why Runtime Differences Matter
21Running JavaScript in the Browser Console
22Creating an HTML File with Inline Script
23External JavaScript Files
24Script Tag Placement and Loading
25Running JavaScript in Node.js REPL
26Executing JavaScript Files with Node
27Console.log for Debugging and Output
28Online JavaScript Playgrounds
29Setting Up a Local Development Environment
30Your First Complete JavaScript Program

1JavaScript: A High-Level Programming Language
2JavaScript's Origins and Purpose
3JavaScript vs ECMAScript
4JavaScript in the Browser
5JavaScript Beyond the Browser
6JavaScript's Key Characteristics
7The JavaScript Ecosystem
8Why Learn JavaScript in 2024+
9What is a JavaScript Engine?
10V8: Chrome and Node.js
11SpiderMonkey: Firefox's Engine
12JavaScriptCore: Safari's Engine
13Parsing and the Abstract Syntax Tree
14Interpretation vs Compilation
15Just-In-Time (JIT) Compilation
16What is a Runtime?
17Browser Runtime: DOM and Web APIs
18Node.js Runtime: Server-Side JavaScript
19Deno and Bun: Alternative Runtimes
20Why Runtime Differences Matter
21Running JavaScript in the Browser Console
22Creating an HTML File with Inline Script
23External JavaScript Files
24Script Tag Placement and Loading
25Running JavaScript in Node.js REPL
26Executing JavaScript Files with Node
27Console.log for Debugging and Output
28Online JavaScript Playgrounds
29Setting Up a Local Development Environment
30Your First Complete JavaScript Program

Lesson 2698 of 2,723·54. Testing in JavaScriptPro lesson

Spying on Existing Functions with jest.spyOn

Wrap real methods to observe calls while preserving or replacing original behavior.

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