Navigating Tree-Sitter Queries with jsluice for JavaScript File Analysis

Welcome to our focused exploration designed to shed light on using the Tree-Sitter query language for crafting effective queries with jsluice. This guide will enhance your ability to analyze JavaScript files with precision.

Understanding Nodes in AST

Each code element, be it a variable, function, or string, is represented as a node in the Abstract Syntax Tree (AST). For example, `identifier` represents variable names, while `function` pertains to functions.

Node Matching

Encapsulate a node type in parentheses to match it. For example, `(identifier)` matches all identifiers in your code.

Attribute Specification

Use `:` to specify node attributes. For instance, `(identifier name: ‘myFunction’)` targets identifiers named ‘myFunction’.

Capturing Patterns

Apply `@` to name a capture pattern. For example, `(identifier) @variable_name` captures all identifiers and tags them as `variable_name`.

Child and Parent Commands

Use `child:` or `parent:` to define node relationships. For example, `(assignment_expression left: (identifier) @variable)` finds variables on the left side of an assignment expression.

Complex Combinations

Combine different node types for more intricate queries. For instance, `(function_declaration name: (identifier) @function_name)` captures specific function declarations.

Operators for Flexibility

Leverage operators like `|` for ‘or’ and `&` for ‘and’. For example, `(identifier name: ‘functionA’ | name: ‘functionB’)` finds identifiers named either ‘functionA’ or ‘functionB’.

Lists and Arrays

Utilize `[]` for specifying a list or an array. For example, `(array (string) @string_array)` targets arrays of strings.