Support for matching multiple arguments with a metavariable (#3009). This is done with a "spread metavariable" operator that looks like $...ARGS. This used to be available only for JavaScript and TypeScript, and is now available for the other languages (Python, Java, Go, C, Ruby, PHP, and OCaml).
A new --optimizations [STR] command-line flag to turn on or off some optimizations. Use "none" to turn off everything and "all" to turn on everything. Just using --optimizations is equivalent to --optimizations all, and not using --optimizations is equivalent to --optimizations none.
JavaScript/TypeScript: Support ... inside JSX text to match any text, as in <a href="foo">...</a>. (#2963)
JavaScript/TypeScript: Support metavariables for JSX attribute values, as in <a href=$X>some text</a>. (#2964)
Single field pattern in JSON, allowing $FLD: { ... } pattern
Config detection in files with many suffix delimiters, like this.that.check.yaml. More concretely: configs end with .yaml, YAML language tests end with .test.yaml, and everything else is handled by its respective language extension (e.g., .py).
Single array field in YAML in a pattern is parsed as a field, not a one element array
Deep expression matches (<... foo ...>) now match within the bodies of anonymous functions (a.k.a. lambda-expressions) and arbitrary language-specific statements (e.g., the Golang go statement)