Facebook created Flow, a static type checker for JavaScript that operates alongside our current JS code. It serves as a flow-oriented typing utility rather than a separate programming language. Flow enhances our productivity significantly, allowing our applications to run faster, be more intelligent, operate with greater confidence, and scale more effectively.
Flow examines the code for discrepancies through the use of static type annotations. These annotations enable us to specify our expectations for how the code should function, and Flow ensures that it operates as intended. Flow is designed to be incrementally integrated; it can be smoothly incorporated and removed from the codebase without causing any disruptions. This feature is particularly beneficial when we wish to activate type-checking for a specific segment of our project.
TypeScript
TypeScript is an open-source, purely object-oriented programming language. It serves as a strongly typed superset of JavaScript that compiles down to standard JavaScript. Microsoft develops and maintains TypeScript under the Apache 2 license. This language is not executed directly in the browser; instead, it requires a compiler to transform and produce a JavaScript file. The source files for TypeScript utilize the ".ts" extension.
TypeScript was created by Anders Hejlsberg and made publicly available on 1 October 2012. Following two years of internal development at Microsoft, TypeScript version 0.9 was launched in 2013. The latest version of TypeScript is 3.4.5, which was released on 24 April 2019.
TypeScript vs. Flow
The following table illustrates the key distinctions between TypeScript and Flow.
| TypeScript | Flow | |
|---|---|---|
| Introduction | It is a typed superset of the JavaScript language. It is open-source and free programming language introduced by Microsoft. | It is a flow-based typing tool, not a programming language. It is a JavaScript static type checker that lives on top of our existing JS code. Flow is built to enable fast and precise code analysis. |
| Design Goal | It is used to identify errors in programs through a balance between correctness and productivity. | It is used to enforce the type soundness/safety. |
| Use Case (popular frameworks integration) | It becomes a better choice when we are working on Angular 2 or higher versions. | If we are working on React, Flow becomes a better choice as it is easily integrated with babel and the already present infrastructure. |
| Benefits | The key benefits are:It uses static typing as a key benefit.It provides useful tools such as code refactoring, auto-completion, navigation.It has excellent IDE support.It can easily integrate with VSCode, which made the editor so popular. | The key benefits are:It uses static typing as a key benefit.It provides a strong procedural analysis.It can easily understand the code.It strongly analyses and controls the program. |
| Features | The main features of Typescript are:Compile-time type checkingType annotationsType erasureType inferenceEnumerated typeInterfacesNamespacesGenericTuples | The main features of Flow are:PrecisionReliabilitySpeedHigh throughputPath sensitivityLow latencyType inferenceReal-time feedbackEasy to integrateEasily understandable JavaScript patterns |
| Services | Along with the provision of static typing, it provides us with great language services and appropriate tooling that includes code refactoring, navigation, and auto-completion. | Along with the provision of static typing, Flow provides us a wide range of inter-procedural analysis and develops an in-depth understanding of our code. |
| Advantages | The advantages of TypeScript are:Popular frameworks support (Vue, React, Angular)Strong communityStrong IDE supportCompatibility with JavaScriptDeclaration files | The advantages of Flow are:Support for any JS fileEasy to integrateStrong understanding of the JS patternsReal-time feedbackTypecastingEasy readabilityEasier modification |
| Disadvantages | The disadvantages of TypeScript are:Another programming languageHarder to integrate with the existing JS projects | The disadvantages of Flow are:Smaller communityNot so focused on the typesSmaller IDE support. |
| Utility size | 42.4 MB | 68.4 MB |
- It uses static typing as a key benefit.
- It provides useful tools such as code refactoring, auto-completion, navigation.
- It has excellent IDE support.
- It can easily integrate with VSCode, which made the editor so popular.
- It uses static typing as a key benefit.
- It provides a strong procedural analysis.
- It can easily understand the code.
- It strongly analyses and controls the program.
- Compile-time type checking
- Type annotations
- Type erasure
- Type inference
- Enumerated type
- Interfaces
- Namespaces
- Generic
- Tuples
- Precision
- Reliability
- Speed
- High throughput
- Path sensitivity
- Low latency
- Type inference
- Real-time feedback
- Easy to integrate
- Easily understandable JavaScript patterns
- Popular frameworks support (Vue, React, Angular)
- Strong community
- Strong IDE support
- Compatibility with JavaScript
- Declaration files
- Support for any JS file
- Easy to integrate
- Strong understanding of the JS patterns
- Real-time feedback
- Typecasting
- Easy readability
- Easier modification
- Another programming language
- Harder to integrate with the existing JS projects
- Smaller community
- Not so focused on the types
- Smaller IDE support.