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NaN incorrectly narrows to 0

microsoft/typescript#36964·111145·Go·2216 天未动·4 条评论·上游最近活跃 ·池内状态:可认领
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<!-- 🚨 STOP 🚨 𝗦𝗧𝗢𝗣 🚨 𝑺𝑻𝑶𝑷 🚨 Half of all issues filed here are duplicates, answered in the FAQ, or not appropriate for the bug tracker. Even if you think you've found a *bug*, please read the FAQ first, especially the Common "Bugs" That Aren't Bugs section! Please help us by doing the following steps before logging an issue: * Search: https://github.com/Microsoft/TypeScript/search?type=Issues * Read the FAQ: https://github.com/Microsoft/TypeScript/wiki/FAQ Please fill in the *entire* template below. --> <!-- Please try to reproduce the issue with the latest published version. It may have already been fixed. For npm: `typescript@next` This is also the 'Nightly' version in the playground: http://www.typescriptlang.org/play/?ts=Nightly --> **TypeScript Version:** 3.9.0-dev.20200222 <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** NaN Truthiness Falsy **Code** ```ts function bool(): boolean { return false; } function number(): number { return NaN; } let a = number(); let b = bool(); const x = a && b; // type = boolean | 0 console.log(x); // prints NaN (which is neither boolean, nor 0) ``` **Expected behavior:** Type of `x` should be `number | boolean`. Since `NaN` isn't a "unit type" like `0`, we can't express `NaN` without using `number`. **Actual behavior:** Type of `x` is `0 | boolean`. **Playground Link:** [playground link](http://www.typescriptlang.org/play/?ts=3.9.0-dev.20200222&ssl=1&ssc=1&pln=8&pc=30#code/GYVwdgxgLglg9mABAIznANgCgJQC4VroCmAhkgN6IBORUIVSwJ6AzkQNyIC+AUKJLASIwIALbIiVHPhHjJiSjToNEAORKrOvHsSiISiALzCxEqdnY7aKIwQw5LPCAhZ6AHrYMAyLyk4B6f0QoAE8AByJbVAxSJAAfRAAGJxcYgDp0OABzTDcLREDEMKoYMCgWNQ0gA) **Related Issues:** <!-- Did you find other bugs that looked similar? --> https://github.com/microsoft/TypeScript/issues/32778 (Incorrectly marked as duplicate?)
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