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Merged
merged 4 commits into from
Nov 23, 2019
Merged

When calculating spreads, merge empty object into nonempty object to … #34853

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25da0a9
When calculating spreads, merge empty object into nonempty object to …
weswigham Oct 31, 2019
8957dfe
Actually accept remainder of baselines
weswigham Oct 31, 2019
7181c2a
Limit simplification to single prop or partial types
weswigham Nov 1, 2019
7be8c79
Merge branch 'master' into specialcase-spread-perf
weswigham Nov 21, 2019
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63 changes: 63 additions & 0 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -12514,6 +12514,61 @@ namespace ts {
return !!(type.flags & TypeFlags.Object) && !isGenericMappedType(type);
}

function isEmptyObjectTypeOrSpreadsIntoEmptyObject(type: Type) {
return isEmptyObjectType(type) || !!(type.flags & (TypeFlags.Null | TypeFlags.Undefined | TypeFlags.BooleanLike | TypeFlags.NumberLike | TypeFlags.BigIntLike | TypeFlags.StringLike | TypeFlags.EnumLike | TypeFlags.NonPrimitive | TypeFlags.Index));
}

function isSinglePropertyAnonymousObjectType(type: Type) {
return !!(type.flags & TypeFlags.Object) &&
!!(getObjectFlags(type) & ObjectFlags.Anonymous) &&
(length(getPropertiesOfType(type)) === 1 || every(getPropertiesOfType(type), p => !!(p.flags & SymbolFlags.Optional)));
}

function tryMergeUnionOfObjectTypeAndEmptyObject(type: UnionType, readonly: boolean): Type | undefined {
if (type.types.length === 2) {
const firstType = type.types[0];
const secondType = type.types[1];
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why only cover a pair of types? is that just the most common case?

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Pretty much. {} | Whatever being roughly equivalent to Partial<whatever> is fairly obvious - {} | Foo | Bar is... less obvious?

if (every(type.types, isEmptyObjectTypeOrSpreadsIntoEmptyObject)) {
return isEmptyObjectType(firstType) ? firstType : isEmptyObjectType(secondType) ? secondType : emptyObjectType;
}
if (isEmptyObjectTypeOrSpreadsIntoEmptyObject(firstType) && isSinglePropertyAnonymousObjectType(secondType)) {
return getAnonymousPartialType(secondType);
}
if (isEmptyObjectTypeOrSpreadsIntoEmptyObject(secondType) && isSinglePropertyAnonymousObjectType(firstType)) {
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why can't we construct a real partial type here? Probably because it would just be expensive and might not exist, right?

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This is just doing the spread operation (skipping privates, only taking spreadable props) here, but also mixing in the Optional flag. I could map it thru partial then feed it back out thru this process, but that's a lot of extra steps (that can fail) for no real gain.

return getAnonymousPartialType(firstType);
}
}

function getAnonymousPartialType(type: Type) {
// gets the type as if it had been spread, but where everything in the spread is made optional
const members = createSymbolTable();
for (const prop of getPropertiesOfType(type)) {
if (getDeclarationModifierFlagsFromSymbol(prop) & (ModifierFlags.Private | ModifierFlags.Protected)) {
// do nothing, skip privates
}
else if (isSpreadableProperty(prop)) {
const isSetonlyAccessor = prop.flags & SymbolFlags.SetAccessor && !(prop.flags & SymbolFlags.GetAccessor);
const flags = SymbolFlags.Property | SymbolFlags.Optional;
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should isSpreadableProperty exclude private/protected instead of needing a separate check?

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Nope - this is pretty much a clone of the property copying code farther down in getSpreadType, but I don't need to bother collecting skippedPrivateMembers (the other type is already known to be empty), and I set the Optional property on every property.

const result = createSymbol(flags, prop.escapedName, readonly ? CheckFlags.Readonly : 0);
result.type = isSetonlyAccessor ? undefinedType : getTypeOfSymbol(prop);
result.declarations = prop.declarations;
result.nameType = prop.nameType;
result.syntheticOrigin = prop;
members.set(prop.escapedName, result);
}
}
const spread = createAnonymousType(
type.symbol,
members,
emptyArray,
emptyArray,
getIndexInfoOfType(type, IndexKind.String),
getIndexInfoOfType(type, IndexKind.Number));
spread.objectFlags |= ObjectFlags.ObjectLiteral | ObjectFlags.ContainsObjectOrArrayLiteral;
return spread;
}
}

/**
* Since the source of spread types are object literals, which are not binary,
* this function should be called in a left folding style, with left = previous result of getSpreadType
Expand All @@ -12533,9 +12588,17 @@ namespace ts {
return left;
}
if (left.flags & TypeFlags.Union) {
const merged = tryMergeUnionOfObjectTypeAndEmptyObject(left as UnionType, readonly);
if (merged) {
return getSpreadType(merged, right, symbol, objectFlags, readonly);
}
return mapType(left, t => getSpreadType(t, right, symbol, objectFlags, readonly));
}
if (right.flags & TypeFlags.Union) {
const merged = tryMergeUnionOfObjectTypeAndEmptyObject(right as UnionType, readonly);
if (merged) {
return getSpreadType(left, merged, symbol, objectFlags, readonly);
}
return mapType(right, t => getSpreadType(left, t, symbol, objectFlags, readonly));
}
if (right.flags & (TypeFlags.BooleanLike | TypeFlags.NumberLike | TypeFlags.BigIntLike | TypeFlags.StringLike | TypeFlags.EnumLike | TypeFlags.NonPrimitive | TypeFlags.Index)) {
Expand Down
26 changes: 13 additions & 13 deletions tests/baselines/reference/objectSpread.types
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Original file line number Diff line number Diff line change
Expand Up @@ -244,7 +244,7 @@ function from16326(this: { header: Header }, header: Header, authToken: string):
>authToken : string

return {
>{ ...this.header, ...header, ...authToken && { authToken } } : { head: string; body: string; authToken: string; } | { authToken: string; head: string; body: string; }
>{ ...this.header, ...header, ...authToken && { authToken } } : { authToken: string; head: string; body: string; }

...this.header,
>this.header : Header
Expand Down Expand Up @@ -277,9 +277,9 @@ function conditionalSpreadBoolean(b: boolean) : { x: number, y: number } {
>13 : 13

o = {
>o = { ...o, ...b && { x: 14 } } : { x: number; y: number; } | { x: number; y: number; }
>o = { ...o, ...b && { x: 14 } } : { x: number; y: number; }
>o : { x: number; y: number; }
>{ ...o, ...b && { x: 14 } } : { x: number; y: number; } | { x: number; y: number; }
>{ ...o, ...b && { x: 14 } } : { x: number; y: number; }

...o,
>o : { x: number; y: number; }
Expand All @@ -292,8 +292,8 @@ function conditionalSpreadBoolean(b: boolean) : { x: number, y: number } {
>14 : 14
}
let o2 = { ...b && { x: 21 }}
>o2 : {}
>{ ...b && { x: 21 }} : { x: number; } | {}
>o2 : { x?: number; }
>{ ...b && { x: 21 }} : { x?: number; }
>b && { x: 21 } : false | { x: number; }
>b : boolean
>{ x: 21 } : { x: number; }
Expand All @@ -318,9 +318,9 @@ function conditionalSpreadNumber(nt: number): { x: number, y: number } {
>16 : 16

o = {
>o = { ...o, ...nt && { x: nt } } : { x: number; y: number; } | { x: number; y: number; }
>o = { ...o, ...nt && { x: nt } } : { x: number; y: number; }
>o : { x: number; y: number; }
>{ ...o, ...nt && { x: nt } } : { x: number; y: number; } | { x: number; y: number; }
>{ ...o, ...nt && { x: nt } } : { x: number; y: number; }

...o,
>o : { x: number; y: number; }
Expand All @@ -333,8 +333,8 @@ function conditionalSpreadNumber(nt: number): { x: number, y: number } {
>nt : number
}
let o2 = { ...nt && { x: nt }}
>o2 : {}
>{ ...nt && { x: nt }} : { x: number; } | {}
>o2 : { x?: number; }
>{ ...nt && { x: nt }} : { x?: number; }
>nt && { x: nt } : 0 | { x: number; }
>nt : number
>{ x: nt } : { x: number; }
Expand All @@ -359,9 +359,9 @@ function conditionalSpreadString(st: string): { x: string, y: number } {
>17 : 17

o = {
>o = { ...o, ...st && { x: st } } : { x: string; y: number; } | { x: string; y: number; }
>o = { ...o, ...st && { x: st } } : { x: string; y: number; }
>o : { x: string; y: number; }
>{ ...o, ...st && { x: st } } : { x: string; y: number; } | { x: string; y: number; }
>{ ...o, ...st && { x: st } } : { x: string; y: number; }

...o,
>o : { x: string; y: number; }
Expand All @@ -374,8 +374,8 @@ function conditionalSpreadString(st: string): { x: string, y: number } {
>st : string
}
let o2 = { ...st && { x: st }}
>o2 : {}
>{ ...st && { x: st }} : { x: string; } | {}
>o2 : { x?: string; }
>{ ...st && { x: st }} : { x?: string; }
>st && { x: st } : "" | { x: string; }
>st : string
>{ x: st } : { x: string; }
Expand Down
4 changes: 2 additions & 2 deletions tests/baselines/reference/objectSpreadIndexSignature.types
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Expand Up @@ -42,9 +42,9 @@ declare const b: boolean;
>b : boolean

indexed3 = { ...b ? indexed3 : undefined };
>indexed3 = { ...b ? indexed3 : undefined } : {} | { [n: string]: number; }
>indexed3 = { ...b ? indexed3 : undefined } : { [n: string]: number; }
>indexed3 : { [n: string]: number; }
>{ ...b ? indexed3 : undefined } : {} | { [n: string]: number; }
>{ ...b ? indexed3 : undefined } : { [n: string]: number; }
>b ? indexed3 : undefined : { [n: string]: number; } | undefined
>b : boolean
>indexed3 : { [n: string]: number; }
Expand Down
80 changes: 80 additions & 0 deletions tests/baselines/reference/objectSpreadRepeatedNullCheckPerf.js
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@@ -0,0 +1,80 @@
//// [objectSpreadRepeatedNullCheckPerf.ts]
interface Props {
readonly a?: string
readonly b?: string
readonly c?: string
readonly d?: string
readonly e?: string
readonly f?: string
readonly g?: string
readonly h?: string
readonly i?: string
readonly j?: string
readonly k?: string
readonly l?: string
readonly m?: string
readonly n?: string
readonly o?: string
readonly p?: string
readonly q?: string
readonly r?: string
readonly s?: string
readonly t?: string
readonly u?: string
readonly v?: string
readonly w?: string
readonly x?: string
readonly y?: string
readonly z?: string
}

function parseWithSpread(config: Record<string, number>): Props {
return {
...config.a !== undefined && { a: config.a.toString() },
...config.b !== undefined && { b: config.b.toString() },
...config.c !== undefined && { c: config.c.toString() },
...config.d !== undefined && { d: config.d.toString() },
...config.e !== undefined && { e: config.e.toString() },
...config.f !== undefined && { f: config.f.toString() },
...config.g !== undefined && { g: config.g.toString() },
...config.h !== undefined && { h: config.h.toString() },
...config.i !== undefined && { i: config.i.toString() },
...config.j !== undefined && { j: config.j.toString() },
...config.k !== undefined && { k: config.k.toString() },
...config.l !== undefined && { l: config.l.toString() },
...config.m !== undefined && { m: config.m.toString() },
...config.n !== undefined && { n: config.n.toString() },
...config.o !== undefined && { o: config.o.toString() },
...config.p !== undefined && { p: config.p.toString() },
...config.q !== undefined && { q: config.q.toString() },
...config.r !== undefined && { r: config.r.toString() },
...config.s !== undefined && { s: config.s.toString() },
...config.t !== undefined && { t: config.t.toString() },
...config.u !== undefined && { u: config.u.toString() },
...config.v !== undefined && { v: config.v.toString() },
...config.w !== undefined && { w: config.w.toString() },
...config.x !== undefined && { x: config.x.toString() },
...config.y !== undefined && { y: config.y.toString() },
...config.z !== undefined && { z: config.z.toString() }
}
}

parseWithSpread({ a: 1, b: 2, z: 26 })

//// [objectSpreadRepeatedNullCheckPerf.js]
"use strict";
var __assign = (this && this.__assign) || function () {
__assign = Object.assign || function(t) {
for (var s, i = 1, n = arguments.length; i < n; i++) {
s = arguments[i];
for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
t[p] = s[p];
}
return t;
};
return __assign.apply(this, arguments);
};
function parseWithSpread(config) {
return __assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign(__assign({}, config.a !== undefined && { a: config.a.toString() }), config.b !== undefined && { b: config.b.toString() }), config.c !== undefined && { c: config.c.toString() }), config.d !== undefined && { d: config.d.toString() }), config.e !== undefined && { e: config.e.toString() }), config.f !== undefined && { f: config.f.toString() }), config.g !== undefined && { g: config.g.toString() }), config.h !== undefined && { h: config.h.toString() }), config.i !== undefined && { i: config.i.toString() }), config.j !== undefined && { j: config.j.toString() }), config.k !== undefined && { k: config.k.toString() }), config.l !== undefined && { l: config.l.toString() }), config.m !== undefined && { m: config.m.toString() }), config.n !== undefined && { n: config.n.toString() }), config.o !== undefined && { o: config.o.toString() }), config.p !== undefined && { p: config.p.toString() }), config.q !== undefined && { q: config.q.toString() }), config.r !== undefined && { r: config.r.toString() }), config.s !== undefined && { s: config.s.toString() }), config.t !== undefined && { t: config.t.toString() }), config.u !== undefined && { u: config.u.toString() }), config.v !== undefined && { v: config.v.toString() }), config.w !== undefined && { w: config.w.toString() }), config.x !== undefined && { x: config.x.toString() }), config.y !== undefined && { y: config.y.toString() }), config.z !== undefined && { z: config.z.toString() });
}
parseWithSpread({ a: 1, b: 2, z: 26 });
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