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Conditional types fail to distribute in properties of mapped types
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<!-- Please try to reproduce the issue with `typescript@next`. It may have already been fixed. -->
**TypeScript Version:** 3.7.0-dev.20190928
<!-- Search terms you tried before logging this (so others can find this issue more easily) -->
**Search Terms:** conditional mapped property union
**Code**
```ts
type NullifyStrings<T> = T extends string ? null : T
type NullifyStringsInPropsWorking<T> = { [K in keyof T]: NullifyStrings<T[K]> }
type NullifyStringsInPropsBroken<T> = { [K in keyof T]: T[K] extends string ? null : T[K] }
type TestType = { a: number | string }
// { a: number | null }
type WorkingReplaceProps = NullifyStringsInPropsWorking<TestType>
// { a: string | number }
type BrokenReplaceProps = NullifyStringsInPropsBroken<TestType>
```
**Expected behavior:**
`NullifyStringsInPropsWorking` and `NullifyStringsInPropsBroken` should be functionally identical - expanding the `NullifyStrings` type alias in `NullifyStringsInPropsWorking` results in the same definition as `NullifyStringsInPropsBroken`.
**Actual behavior:**
`NullifyStringsInPropsWorking` and `NullifyStringsInPropsBroken` have different behaviour - `BrokenReplaceProps` has type `{ a: string | number }` instead of the expected `{ a: number | null }`.
**Playground Link:** <!-- A link to a TypeScript Playground "Share" link which demonstrates this behavior --> [Link](https://www.typescriptlang.org/play/?ts=Nightly#code/C4TwDgpgBAcgrgGwQSwGYgMrAE7IHYDmAzgDwAqAfFALxRlQQAewEeAJkVETvgVAPxQ8iBFA…
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