JavaScript runtime features for CloudFront Functions - Amazon CloudFront
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JavaScript runtime features for CloudFront Functions

The Amazon CloudFront Functions JavaScript runtime environment is compliant with ECMAScript (ES) version 5.1 and also supports some features of ES versions 6 through 12.

We recommend that you use runtime 2.0 for the most up to date features. Note that runtime 2.0 has the following changes compared to 1.0:

  • Buffer module methods are available.

  • The following non-standard string prototype methods are not available:

    • String.prototype.bytesFrom()

    • String.prototype.fromBytes()

    • String.prototype.fromUTF8()

    • String.prototype.toBytes()

    • String.prototype.toUTF8()

  • The cryptographic module has the following changes:

    • hash.digest() - Return type is changed to Buffer if no encoding is provided

    • hmac.digest() - Return type is changed to Buffer if no encoding is provided

  • Additional new features are noted in JavaScript runtime 2.0 features for CloudFront Functions.

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