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

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

For the most up-to-date features, we recommend that you use JavaScript runtime 2.0.

The JavaScript runtime 2.0 features 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

  • For more information about additional new features, see JavaScript runtime 2.0 features for CloudFront Functions.

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