From 7a2c7ad37420ad8f11652a6b87116c1b20fca802 Mon Sep 17 00:00:00 2001 From: Nathan Shively-Sanders Date: Thu, 3 Nov 2016 09:41:31 -0700 Subject: [PATCH] Spread handles index signatures from singleton spreads I broke it when simplifying the logic earlier. --- src/compiler/checker.ts | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index 872aad6b046..3475a9d52c6 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -5888,8 +5888,17 @@ namespace ts { Debug.assert(!!(left.flags & TypeFlags.Object) && !!(right.flags & TypeFlags.Object), "Only object types may be spread."); const members = createMap(); const skippedPrivateMembers = createMap(); - const stringIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.String), getIndexInfoOfType(right, IndexKind.String)); - const numberIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.Number), getIndexInfoOfType(right, IndexKind.Number)); + let stringIndexInfo: IndexInfo; + let numberIndexInfo: IndexInfo; + if (left === emptyObjectType) { + // for the first spread element, left === emptyObjectType, so take the right's string indexer + stringIndexInfo = getIndexInfoOfType(right, IndexKind.String); + numberIndexInfo = getIndexInfoOfType(right, IndexKind.Number); + } + else { + stringIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.String), getIndexInfoOfType(right, IndexKind.String)); + numberIndexInfo = unionSpreadIndexInfos(getIndexInfoOfType(left, IndexKind.Number), getIndexInfoOfType(right, IndexKind.Number)); + } const isFromSpread = right.symbol !== symbol; for (const rightProp of getPropertiesOfType(right)) {