eslint-plugin-svelte
Version:
ESLint plugin for Svelte using AST
71 lines (70 loc) • 2.7 kB
JavaScript
import { createRule } from '../utils/index.js';
import { equalTokens } from '../utils/ast-utils.js';
export default createRule('no-dupe-on-directives', {
meta: {
docs: {
description: 'disallow duplicate `on:` directives',
category: 'Possible Errors',
recommended: true
},
schema: [],
messages: {
duplication: 'This `on:{{type}}` directive is the same and duplicate directives in L{{lineNo}}.'
},
type: 'problem'
},
create(context) {
const sourceCode = context.sourceCode;
const directiveDataMap = new Map();
return {
SvelteDirective(node) {
if (node.kind !== 'EventHandler')
return;
const directiveDataList = directiveDataMap.get(node.key.name.name);
if (!directiveDataList) {
directiveDataMap.set(node.key.name.name, [
{
expression: node.expression,
nodes: [node]
}
]);
return;
}
const directiveData = directiveDataList.find((data) => {
if (!data.expression || !node.expression) {
return data.expression === node.expression;
}
return equalTokens(data.expression, node.expression, sourceCode);
});
if (!directiveData) {
directiveDataList.push({
expression: node.expression,
nodes: [node]
});
return;
}
directiveData.nodes.push(node);
},
'SvelteStartTag:exit'() {
for (const [type, directiveDataList] of directiveDataMap) {
for (const { nodes } of directiveDataList) {
if (nodes.length < 2) {
continue;
}
for (const node of nodes) {
context.report({
node,
messageId: 'duplication',
data: {
type,
lineNo: String((nodes[0] !== node ? nodes[0] : nodes[1]).loc.start.line)
}
});
}
}
}
directiveDataMap.clear();
}
};
}
});