> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/eslint/eslint/llms.txt
> Use this file to discover all available pages before exploring further.

# SourceCode

> Represents parsed JavaScript source code

The `SourceCode` class represents parsed source code and provides methods for working with the AST (Abstract Syntax Tree), tokens, comments, and source text.

## Constructor

```javascript theme={null}
const { SourceCode } = require("eslint");
const sourceCode = new SourceCode(textOrConfig, ast);
```

<ParamField path="textOrConfig" type="string | object" required>
  Either the source code text or a configuration object.

  <Expandable title="config properties">
    <ParamField path="text" type="string" required>
      The source code text.
    </ParamField>

    <ParamField path="ast" type="ASTNode" required>
      The Program node of the AST.
    </ParamField>

    <ParamField path="hasBOM" type="boolean">
      Indicates if the text has a Unicode BOM.
    </ParamField>

    <ParamField path="parserServices" type="object">
      Parser services provided by the parser.
    </ParamField>

    <ParamField path="scopeManager" type="ScopeManager">
      The scope manager for the source code.
    </ParamField>

    <ParamField path="visitorKeys" type="object">
      Visitor keys to traverse the AST.
    </ParamField>
  </Expandable>
</ParamField>

<ParamField path="ast" type="ASTNode">
  The Program node (when using the simple string constructor).
</ParamField>

## Properties

### text

```javascript theme={null}
const text = sourceCode.text;
```

<ResponseField name="text" type="string">
  The full source code text.
</ResponseField>

### ast

```javascript theme={null}
const ast = sourceCode.ast;
```

<ResponseField name="ast" type="ASTNode">
  The Program node of the Abstract Syntax Tree.
</ResponseField>

### lines

```javascript theme={null}
const lines = sourceCode.lines;
```

<ResponseField name="lines" type="string[]">
  Array of lines in the source code (split by line breaks).
</ResponseField>

### hasBOM

```javascript theme={null}
const hasBOM = sourceCode.hasBOM;
```

<ResponseField name="hasBOM" type="boolean">
  Whether the source code has a Unicode Byte Order Mark.
</ResponseField>

### parserServices

```javascript theme={null}
const services = sourceCode.parserServices;
```

<ResponseField name="parserServices" type="object">
  Additional services provided by the parser (e.g., TypeScript type information).
</ResponseField>

### scopeManager

```javascript theme={null}
const scopeManager = sourceCode.scopeManager;
```

<ResponseField name="scopeManager" type="ScopeManager">
  The scope manager containing scope analysis results.
</ResponseField>

### visitorKeys

```javascript theme={null}
const visitorKeys = sourceCode.visitorKeys;
```

<ResponseField name="visitorKeys" type="object">
  Visitor keys for traversing the AST.
</ResponseField>

## Methods

### getText()

Gets the source code text for a node or token.

```javascript theme={null}
const text = sourceCode.getText(nodeOrToken, beforeCount, afterCount);
```

<ParamField path="nodeOrToken" type="ASTNode | Token">
  The node or token to get text for. If omitted, returns entire source.
</ParamField>

<ParamField path="beforeCount" type="number" default="0">
  Number of characters before the node to include.
</ParamField>

<ParamField path="afterCount" type="number" default="0">
  Number of characters after the node to include.
</ParamField>

<ResponseField name="text" type="string">
  The source code text.
</ResponseField>

### getLines()

Gets the source code lines.

```javascript theme={null}
const lines = sourceCode.getLines();
```

<ResponseField name="lines" type="string[]">
  Array of source code lines.
</ResponseField>

### getAllComments()

Gets all comments in the source code.

```javascript theme={null}
const comments = sourceCode.getAllComments();
```

<ResponseField name="comments" type="Token[]">
  Array of comment tokens.
</ResponseField>

### getComments()

Gets comments for a specific node.

```javascript theme={null}
const comments = sourceCode.getComments(node);
```

<ParamField path="node" type="ASTNode" required>
  The node to get comments for.
</ParamField>

<ResponseField name="comments" type="object">
  <Expandable title="properties">
    <ResponseField name="leading" type="Token[]">
      Comments before the node.
    </ResponseField>

    <ResponseField name="trailing" type="Token[]">
      Comments after the node.
    </ResponseField>
  </Expandable>
</ResponseField>

### getLoc()

Gets the location information for a node or token.

```javascript theme={null}
const loc = sourceCode.getLoc(nodeOrToken);
```

<ParamField path="nodeOrToken" type="ASTNode | Token" required>
  The node or token.
</ParamField>

<ResponseField name="loc" type="object">
  <Expandable title="properties">
    <ResponseField name="start" type="object">
      Start position with `line` and `column` (1-based).
    </ResponseField>

    <ResponseField name="end" type="object">
      End position with `line` and `column` (1-based).
    </ResponseField>
  </Expandable>
</ResponseField>

### getRange()

Gets the range for a node or token.

```javascript theme={null}
const range = sourceCode.getRange(nodeOrToken);
```

<ParamField path="nodeOrToken" type="ASTNode | Token" required>
  The node or token.
</ParamField>

<ResponseField name="range" type="[number, number]">
  The \[start, end] character indices (0-based).
</ResponseField>

### getTokens()

Gets tokens for a node.

```javascript theme={null}
const tokens = sourceCode.getTokens(node, beforeCount, afterCount);
```

<ParamField path="node" type="ASTNode" required>
  The node to get tokens for.
</ParamField>

<ParamField path="beforeCount" type="number" default="0">
  Number of tokens before the node to include.
</ParamField>

<ParamField path="afterCount" type="number" default="0">
  Number of tokens after the node to include.
</ParamField>

<ResponseField name="tokens" type="Token[]">
  Array of tokens.
</ResponseField>

### getFirstToken()

Gets the first token of a node.

```javascript theme={null}
const token = sourceCode.getFirstToken(node, options);
```

<ParamField path="node" type="ASTNode" required>
  The node.
</ParamField>

<ParamField path="options" type="number | function | object">
  Skip count, filter function, or options object.
</ParamField>

<ResponseField name="token" type="Token | null">
  The first token, or null if not found.
</ResponseField>

### getLastToken()

Gets the last token of a node.

```javascript theme={null}
const token = sourceCode.getLastToken(node, options);
```

<ParamField path="node" type="ASTNode" required>
  The node.
</ParamField>

<ParamField path="options" type="number | function | object">
  Skip count, filter function, or options object.
</ParamField>

<ResponseField name="token" type="Token | null">
  The last token, or null if not found.
</ResponseField>

### getTokenBefore()

Gets the token before a node or token.

```javascript theme={null}
const token = sourceCode.getTokenBefore(nodeOrToken, options);
```

<ParamField path="nodeOrToken" type="ASTNode | Token" required>
  The node or token.
</ParamField>

<ParamField path="options" type="number | function | object">
  Skip count, filter function, or options object.
</ParamField>

<ResponseField name="token" type="Token | null">
  The previous token, or null if not found.
</ResponseField>

### getTokenAfter()

Gets the token after a node or token.

```javascript theme={null}
const token = sourceCode.getTokenAfter(nodeOrToken, options);
```

<ParamField path="nodeOrToken" type="ASTNode | Token" required>
  The node or token.
</ParamField>

<ParamField path="options" type="number | function | object">
  Skip count, filter function, or options object.
</ParamField>

<ResponseField name="token" type="Token | null">
  The next token, or null if not found.
</ResponseField>

### getFirstTokenBetween()

Gets the first token between two nodes or tokens.

```javascript theme={null}
const token = sourceCode.getFirstTokenBetween(left, right, options);
```

<ParamField path="left" type="ASTNode | Token" required>
  The left node or token.
</ParamField>

<ParamField path="right" type="ASTNode | Token" required>
  The right node or token.
</ParamField>

<ParamField path="options" type="number | function | object">
  Skip count, filter function, or options object.
</ParamField>

<ResponseField name="token" type="Token | null">
  The first token between, or null if not found.
</ResponseField>

### getTokensBetween()

Gets all tokens between two nodes or tokens.

```javascript theme={null}
const tokens = sourceCode.getTokensBetween(left, right, padding);
```

<ParamField path="left" type="ASTNode | Token" required>
  The left node or token.
</ParamField>

<ParamField path="right" type="ASTNode | Token" required>
  The right node or token.
</ParamField>

<ParamField path="padding" type="number" default="0">
  Number of extra tokens to include on each side.
</ParamField>

<ResponseField name="tokens" type="Token[]">
  Array of tokens between the two nodes/tokens.
</ResponseField>

### getTokenByRangeStart()

Gets a token by its range start position.

```javascript theme={null}
const token = sourceCode.getTokenByRangeStart(index, options);
```

<ParamField path="index" type="number" required>
  The range start index.
</ParamField>

<ParamField path="options" type="object">
  Options for the search.
</ParamField>

<ResponseField name="token" type="Token | null">
  The token at that position, or null.
</ResponseField>

### getNodeByRangeIndex()

Gets the deepest node containing a given index.

```javascript theme={null}
const node = sourceCode.getNodeByRangeIndex(index);
```

<ParamField path="index" type="number" required>
  The character index.
</ParamField>

<ResponseField name="node" type="ASTNode | null">
  The deepest node containing the index, or null.
</ResponseField>

### isSpaceBetween()

Checks if there is whitespace between two nodes or tokens.

```javascript theme={null}
const hasSpace = sourceCode.isSpaceBetween(first, second);
```

<ParamField path="first" type="ASTNode | Token" required>
  The first node or token.
</ParamField>

<ParamField path="second" type="ASTNode | Token" required>
  The second node or token.
</ParamField>

<ResponseField name="hasSpace" type="boolean">
  True if there is whitespace between them.
</ResponseField>

### getScope()

Gets the scope for a node.

```javascript theme={null}
const scope = sourceCode.getScope(node);
```

<ParamField path="node" type="ASTNode" required>
  The node to get the scope for.
</ParamField>

<ResponseField name="scope" type="Scope">
  The scope object.
</ResponseField>

### markVariableAsUsed()

Marks a variable as used in a specific scope.

```javascript theme={null}
const found = sourceCode.markVariableAsUsed(name, node);
```

<ParamField path="name" type="string" required>
  The variable name.
</ParamField>

<ParamField path="node" type="ASTNode">
  The node to start the search from.
</ParamField>

<ResponseField name="found" type="boolean">
  True if the variable was found and marked.
</ResponseField>

### getAncestors()

Gets the ancestor nodes of a given node.

```javascript theme={null}
const ancestors = sourceCode.getAncestors(node);
```

<ParamField path="node" type="ASTNode" required>
  The node.
</ParamField>

<ResponseField name="ancestors" type="ASTNode[]">
  Array of ancestor nodes from closest to farthest.
</ResponseField>

### getDeclaredVariables()

Gets variables declared by a node.

```javascript theme={null}
const variables = sourceCode.getDeclaredVariables(node);
```

<ParamField path="node" type="ASTNode" required>
  The node.
</ParamField>

<ResponseField name="variables" type="Variable[]">
  Array of declared variables.
</ResponseField>

## Examples

<Tabs>
  <Tab title="Getting Text">
    ```javascript theme={null}
    const { SourceCode } = require("eslint");

    // Assuming you have an AST node
    const text = sourceCode.getText(node);
    console.log(text);

    // Get text with surrounding context
    const textWithContext = sourceCode.getText(node, 2, 2);
    console.log(textWithContext);
    ```
  </Tab>

  <Tab title="Working with Tokens">
    ```javascript theme={null}
    // Get all tokens for a node
    const tokens = sourceCode.getTokens(node);

    // Get first and last tokens
    const first = sourceCode.getFirstToken(node);
    const last = sourceCode.getLastToken(node);

    // Get tokens between two nodes
    const between = sourceCode.getTokensBetween(leftNode, rightNode);

    console.log(tokens, first, last, between);
    ```
  </Tab>

  <Tab title="Checking Spacing">
    ```javascript theme={null}
    // Check if there's whitespace between tokens
    const hasSpace = sourceCode.isSpaceBetween(token1, token2);

    if (!hasSpace) {
      context.report({
        node,
        message: "Expected space between tokens."
      });
    }
    ```
  </Tab>

  <Tab title="Scope Analysis">
    ```javascript theme={null}
    // Get the scope for a node
    const scope = sourceCode.getScope(node);

    // Get declared variables
    const variables = sourceCode.getDeclaredVariables(node);

    // Mark a variable as used
    sourceCode.markVariableAsUsed("myVar", node);

    console.log(scope, variables);
    ```
  </Tab>
</Tabs>

## Usage in Rules

The `SourceCode` object is available in rules through the `context` object:

```javascript theme={null}
module.exports = {
  create(context) {
    const sourceCode = context.sourceCode;

    return {
      Identifier(node) {
        const text = sourceCode.getText(node);
        const token = sourceCode.getFirstToken(node);
        
        // Your rule logic here
      }
    };
  }
};
```