Documentation Index
Fetch the complete documentation index at: https://mintlify.com/mpsuesser/effect-oxlint/llms.txt
Use this file to discover all available pages before exploring further.
The SourceCode module provides effectful wrappers around every method on oxlint’s SourceCode object. Instead of accessing ctx.sourceCode directly and handling null returns, each function reads from the RuleContext service and returns an Effect<T, never, RuleContext> that you can yield* inside a visitor handler. Nullable results are lifted to Option — empty arrays stay as empty arrays.
withSourceCode pattern
Internally every function in this module uses the same withSourceCode helper:
const withSourceCode = <A>(
fn: (sc: OxlintSourceCode) => A
): Effect.Effect<A, never, RuleContext> =>
Effect.service(RuleContext).pipe(Effect.map((ctx) => fn(ctx.sourceCode)));
import { RuleContext } from 'effect-oxlint';
import * as Effect from 'effect/Effect';
const myQuery = Effect.service(RuleContext).pipe(
Effect.map((ctx) => {
const text = ctx.sourceCode.getText(node);
const tokens = ctx.sourceCode.getTokens(node);
return { text, tokens };
})
);
Source text
getText
export const getText = (): Effect.Effect<string, never, RuleContext>
const text = yield* SourceCode.getText();
getNodeText
export const getNodeText = (
node: ESTree.Node,
beforeCount?: number,
afterCount?: number
): Effect.Effect<string, never, RuleContext>
beforeCount and afterCount to include additional characters before and after the node’s range.
The AST node whose source text you want.
Number of characters to include before the node’s start offset.
Number of characters to include after the node’s end offset.
const text = yield* SourceCode.getNodeText(node);
const withContext = yield* SourceCode.getNodeText(node, 10, 10);
getLines
export const getLines = (): Effect.Effect<ReadonlyArray<string>, never, RuleContext>
ReadonlyArray<string>.
Ancestry
getAncestors
export const getAncestors = (
node: ESTree.Node
): Effect.Effect<ReadonlyArray<ESTree.Node>, never, RuleContext>
node ordered from innermost to outermost. The result array does not include the node itself.
oxlint’s upstream getAncestors types the return as Node[] where Node is the base Span interface. The wrapper casts to ReadonlyArray<ESTree.Node> at the FFI boundary — the runtime values are always full ESTree nodes.
Location and range
getLocFromIndex
export const getLocFromIndex = (
offset: number
): Effect.Effect<LineColumn, never, RuleContext>
{ line, column } location.
getIndexFromLoc
export const getIndexFromLoc = (
loc: LineColumn
): Effect.Effect<number, never, RuleContext>
{ line, column } location to a 0-based source offset.
getRange
export const getRange = (
nodeOrToken: ESTree.Node | Token | Comment
): Effect.Effect<Range, never, RuleContext>
[start, end] range tuple for a node, token, or comment.
getNodeByRangeIndex
export const getNodeByRangeIndex = (
offset: number
): Effect.Effect<Option.Option<ESTree.Node>, never, RuleContext>
Option.none() when no node covers that position.
Token queries
getFirstToken
export const getFirstToken = (
node: ESTree.Node
): Effect.Effect<Option.Option<Token>, never, RuleContext>
Option.none() if the node has no tokens.
getLastToken
export const getLastToken = (
node: ESTree.Node
): Effect.Effect<Option.Option<Token>, never, RuleContext>
Option.none() if the node has no tokens.
getTokens
export const getTokens = (
node: ESTree.Node
): Effect.Effect<ReadonlyArray<Token>, never, RuleContext>
getTokenBefore
export const getTokenBefore = (
nodeOrToken: ESTree.Node | Token | Comment
): Effect.Effect<Option.Option<Token>, never, RuleContext>
Option.none() if there is none.
getTokenAfter
export const getTokenAfter = (
nodeOrToken: ESTree.Node | Token | Comment
): Effect.Effect<Option.Option<Token>, never, RuleContext>
Option.none() if there is none.
getTokensBetween
export const getTokensBetween = (
left: ESTree.Node | Token | Comment,
right: ESTree.Node | Token | Comment
): Effect.Effect<ReadonlyArray<Token>, never, RuleContext>
left and right.
getFirstTokenBetween
export const getFirstTokenBetween = (
left: ESTree.Node | Token | Comment,
right: ESTree.Node | Token | Comment
): Effect.Effect<Option.Option<Token>, never, RuleContext>
left and right, or Option.none() if there are none.
getTokenByRangeStart
export const getTokenByRangeStart = (
offset: number
): Effect.Effect<Option.Option<Token>, never, RuleContext>
Option.none() when no token starts at that position.
export const getAllComments = (): Effect.Effect<ReadonlyArray<Comment>, never, RuleContext>
export const getCommentsBefore = (
nodeOrToken: ESTree.Node | Token | Comment
): Effect.Effect<ReadonlyArray<Comment>, never, RuleContext>
nodeOrToken.
export const getCommentsAfter = (
nodeOrToken: ESTree.Node | Token | Comment
): Effect.Effect<ReadonlyArray<Comment>, never, RuleContext>
nodeOrToken.
export const getCommentsInside = (
node: ESTree.Node
): Effect.Effect<ReadonlyArray<Comment>, never, RuleContext>
node.
export const getJSDocComment = (
node: ESTree.Node
): Effect.Effect<Option.Option<Comment>, never, RuleContext>
Option.none().
getJSDocComment is deprecated upstream. Prefer getCommentsBefore and filter for block comments starting with /** instead.
export const commentsExistBetween = (
left: ESTree.Node | Token | Comment,
right: ESTree.Node | Token | Comment
): Effect.Effect<boolean, never, RuleContext>
true if at least one comment exists between left and right.
Scope queries
getScope
export const getScope = (
node: ESTree.Node
): Effect.Effect<Scope, never, RuleContext>
Scope for a node. Combine with the Scope module to walk up the scope chain or look up variables.
getDeclaredVariables
export const getDeclaredVariables = (
node: ESTree.Node
): Effect.Effect<ReadonlyArray<Variable>, never, RuleContext>
VariableDeclaration).
isGlobalReference
export const isGlobalReference = (
node: ESTree.Node
): Effect.Effect<boolean, never, RuleContext>
true when node is a reference to a global variable.
markVariableAsUsed
export const markVariableAsUsed = (
name: string,
refNode?: ESTree.Node
): Effect.Effect<boolean, never, RuleContext>
refNode (or the current scope when omitted). Returns true on success. This is typically used to suppress no-unused-vars false positives.
Spacing
isSpaceBetween
export const isSpaceBetween = (
first: ESTree.Node | Token | Comment,
second: ESTree.Node | Token | Comment
): Effect.Effect<boolean, never, RuleContext>
true when there is at least one whitespace character between first and second.
Usage example
The following visitor handler combines several queries to inspect the text and tokens of a detected node:
import { Diagnostic, Rule, SourceCode } from 'effect-oxlint';
import * as Effect from 'effect/Effect';
import * as Option from 'effect/Option';
const noSemiRule = Rule.define({
name: 'check-semicolon',
meta: Rule.meta({ type: 'layout', description: 'Enforce semicolons' }),
create: function* () {
return {
ExpressionStatement: (node) =>
Effect.gen(function* () {
const lastToken = yield* SourceCode.getLastToken(node);
if (Option.isNone(lastToken)) return;
if (lastToken.value.value !== ';') {
const before = yield* SourceCode.getTokenBefore(lastToken.value);
yield* Effect.log(`Missing semicolon after token: ${Option.getOrElse(before, () => ({ value: '?' })).value}`);
}
})
};
}
});
