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Support type narrowing for non-callable node #136

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Merged
merged 2 commits into from
Jun 22, 2025
Merged

Support type narrowing for non-callable node #136

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1b19109
Fix tests
Xvezda Jun 22, 2025
aac5ab6
Type narrowing for non-callable node
Xvezda Jun 22, 2025
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22 changes: 16 additions & 6 deletions src/rules/no-undocumented-throws.js
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Original file line number Diff line number Diff line change
Expand Up @@ -143,13 +143,23 @@ module.exports = createRule({
const calleeDeclaration = getCalleeDeclaration(services, node);
if (!calleeDeclaration) return;

const signature = getCallSignature(
services,
services.tsNodeToESTreeNodeMap.get(calleeDeclaration)
);
switch (node.type) {
case AST_NODE_TYPES.CallExpression:
case AST_NODE_TYPES.NewExpression: {
if (services.tsNodeToESTreeNodeMap.has(calleeDeclaration)) {
const signature = getCallSignature(
services,
services.tsNodeToESTreeNodeMap.get(calleeDeclaration)
);

const returnType = signature?.getReturnType();
if (returnType && isGeneratorLike(returnType)) return;
const returnType = signature?.getReturnType();
Comment on lines +149 to +155
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Copilot AI Jun 22, 2025

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[nitpick] Generator-like checks only run when the declaration is in tsNodeToESTreeNodeMap. If the signature isn’t mapped there, generator return types won’t be skipped. Consider obtaining the signature unconditionally or adjusting the guard.

Suggested change
if (services.tsNodeToESTreeNodeMap.has(calleeDeclaration)) {
const signature = getCallSignature(
services,
services.tsNodeToESTreeNodeMap.get(calleeDeclaration)
);
const returnType = signature?.getReturnType();
if (returnType && isGeneratorLike(returnType)) return;
const returnType = signature?.getReturnType();
const signature = checker.getResolvedSignature(calleeDeclaration);
if (signature) {
const returnType = signature.getReturnType();

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if (returnType && isGeneratorLike(returnType)) return;
}
break;
}
default:
break;
}

/** @type {import('typescript').JSDocThrowsTag[]} */
const comments = [];
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13 changes: 7 additions & 6 deletions src/utils.js
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Original file line number Diff line number Diff line change
Expand Up @@ -350,11 +350,14 @@ const getCalleeDeclaration = (services, node) => {
const calleeNode = getCallee(node);
if (!calleeNode) return null;

const symbol = services
.getTypeAtLocation(calleeNode)
.symbol;
const type = services.getTypeAtLocation(calleeNode);

if (!symbol || !symbol.valueDeclaration) {
if (type.symbol?.valueDeclaration) {
declaration = type.symbol.valueDeclaration;
} else if (type.symbol?.declarations?.length) {
// If there are multiple declarations, we take the first one.
declaration = type.symbol.declarations[0];
Comment on lines +358 to +359
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Copilot AI Jun 22, 2025

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[nitpick] Although you guard for declarations?.length above, consider capturing const decls = type.symbol.declarations to avoid reaccessing the optional chain—this also makes the assignment clearer and prevents any future undefined access.

Suggested change
// If there are multiple declarations, we take the first one.
declaration = type.symbol.declarations[0];
const decls = type.symbol.declarations;
// If there are multiple declarations, we take the first one.
declaration = decls[0];

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} else {
const declarations = services
.getSymbolAtLocation(calleeNode)
?.declarations;
Expand All @@ -363,8 +366,6 @@ const getCalleeDeclaration = (services, node) => {

// If there are multiple declarations, we take the first one.
declaration = declarations[0];
} else {
declaration = symbol.valueDeclaration;
}
}
if (!declaration) return null;
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