How should I practice Resilient Fake API Client?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Tesla phone screen problems in FastPrep.

Is Resilient Fake API Client associated with Tesla?

FastPrep tags this as a Tesla phone screen coding practice problem when the problem catalog has that company and stage context.

Problem · String

Resilient Fake API Client

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TeslaFULLTIMEPHONE SCREEN

Problem statement

A fake API provides one response per attempt through parallel arrays statuses and bodies. Process at most maxAttempts responses in order.

A status from 200 through 299 is successful. Parse its body using the closed JSON grammar below. Return SUCCESS: followed by the object with keys sorted lexicographically, or JSON_ERROR when parsing fails.
Status 429 and every status from 500 through 599 are retryable while attempts remain.
Every other status is terminal; return HTTP_n, where n is the status.
If every permitted attempt is retryable, return EXHAUSTED.

An accepted body is exactly {} or a whitespace-free object such as {"b":"two","a":"1"}. Keys are unique, nonempty strings. Values may be empty. Key and value characters are limited to ASCII letters, digits, underscores, and hyphens. Escapes, nesting, arrays, numbers, booleans, null, and whitespace are invalid.

Function

handleResponses(statuses: int[], bodies: String[], maxAttempts: int) → String

Examples

Example 1

statuses = [429,503,200]bodies = ["ignored","ignored","{\"b\":\"two\",\"a\":\"1\"}"]maxAttempts = 3return = "SUCCESS:{\"a\":\"1\",\"b\":\"two\"}"

The client retries the rate limit and server failure. The successful body is valid and its keys are canonicalized.

Example 2

statuses = [500,429,503,200]bodies = ["","","","{}"]maxAttempts = 3return = "EXHAUSTED"

Only three attempts are permitted, and all three observed statuses are retryable. The later success is not consumed.

Example 3

statuses = [200]bodies = ["{\"a\":  \"b\"}"]maxAttempts = 1return = "JSON_ERROR"

Whitespace is outside the accepted grammar, so a successful HTTP status still produces a parse error.

Constraints

1 <= statuses.length == bodies.length <= 100000.
1 <= maxAttempts <= statuses.length.
100 <= statuses[i] <= 599.
0 <= bodies[i].length <= 1000.
A body is parsed only for the first successful status.
Accepted object keys are unique and the total output fits in memory.