René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"5.6 regression: Array.prototype.reduce type inference regression","articleBody":"### 🔎 Search Terms\n\nInference, Reduce\n\n### 🕗 Version \u0026 Regression Information\n\n- This changed between versions 5.5.4 and 5.6.0-beta (still happening in 5.6.1-rc)\n\n### ⏯ Playground Link\n\nhttps://www.typescriptlang.org/play/?ts=5.6.1-rc#code/JYOwLgpgTgZghgYwgAgMoHsC2EAqBPABxQG8AoZC5CEAVwC40sIBRWzAblIF9TTqbMjbKwHIylZAEFkAXmQBGADTlKAIVnIATMokBhDQGYdlACIaALMp6kAJhAQAbOFBQJ0IAM5hkANzgOPBgxsfCIAbQBdTlI3T28PTH8HCC8RDT8AgDoXGxokAAoVCnzMUBFFX38ASlkAPmQAWTgwAAtM0pASstoKjMz+KuMKYJY2TJNlKs4EpJSwEU4AekXkAD0AfiA\n\n### 💻 Code\n\n```ts\r\ninterface SomeType {\r\n    enu: SomeEnum;\r\n}\r\n\r\nenum SomeEnum {\r\n    A = 1,\r\n    B = 2,\r\n    C = 3,\r\n    D = 4,\r\n}\r\n\r\ndeclare const vals: SomeType[];\r\n\r\nconst smallestEnu = vals.reduce(\r\n    (minEnu, val) =\u003e Math.min(minEnu, val.enu),\r\n    SomeEnum.D,\r\n);\r\nsmallestEnu;\r\n// ^?\r\n```\r\n\n\n### 🙁 Actual behavior\n\n`smallestEnu` has type `number`\n\n### 🙂 Expected behavior\n\n`smallestEnu` has type `SomeEnum` as it did in previous releases\n\n### Additional information about the issue\n\nInterestingly, this does not repro if you remove the container type:\r\nhttps://www.typescriptlang.org/play/?ts=5.6.1-rc#code/KYOwrgtgBAyg9hYBRc0DeAoK2oEEoC8UAjADRY4BChUATOTlAMI0DMDOAIjQCzkC+GDABNgAYwA2AQwBOwKGLggAzgBcooSMoBcsBMlQBtALoBuIYpXrlEKRInA1KMDU0RlAOjnCwY4AAoKbH8IAEsQZ1INcABKQgA+KABZKVUACw8wkBDwyOiwGI5seERnCA9OchjzGzsHJ3BzAHomqAA9AH4MIA\r\n\r\n(Google note: relevant source location http://shortn/_JgMRGaMa4e)","author":{"url":"https://github.com/trevorade","@type":"Person","name":"trevorade"},"datePublished":"2024-08-26T19:41:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/59763/TypeScript/issues/59763"}