SKU Normalizer

Reliability

Fully deterministic: the same code under the same rules always gives the same answer, and the order is fixed at trim, Unicode NFKC, strip diacritics, case, allowed-character policy, collapse separators, segment padding, prefix, suffix — nine stages, with prefix and suffix reported separately. The order is part of the answer, and one place inside it decides whether a code is repaired or refused: the allowed-character policy runs before the separator collapse, so under onDisallowed REJECT a character the set does not permit fails the call even when collapseSeparators would have turned it into the separator a moment later. A space is such a character under every allowedCharacters value. Normalising an already-normalised code changes nothing, with one honest exception: prefix and suffix are added on every call, so a code that carries them is not stable under a second pass with the same rules. A property this skill does not implement is refused, not ignored: an unknown top-level property is a broken request and comes back as the platform's TOOL_INPUT_INVALID, while an unknown property inside rules — or a value outside one of the rules' closed sets — is this skill's own SKU_RULES_INVALID. Failures, and what to do about each. SKU_INVALID — trigger: the code is an empty string, holds a control character, or skus is empty, longer than 5000 entries, or holds something that is not a string; retryable: no, the same request always fails; next: fix or drop the entry we name by position, or split a batch over 5000 codes. SKU_TOO_LONG — trigger: a code is longer than 128 characters before normalisation; retryable: no; next: shorten the code, since we will not truncate an identifier for you. A code past the 1 MiB request ceiling is a payload problem instead, and comes back as a validation error. SKU_DISALLOWED_CHARACTER — trigger: you set rules.onDisallowed to REJECT and the code holds a character rules.allowedCharacters does not permit, which includes a space and includes any non-ASCII letter that survived NFKC and the diacritic strip; retryable: no; next: use REMOVE or REPLACE if you want the code cleaned, or correct the character at the position we report. SKU_RULES_INVALID — trigger: the rules contradict themselves — a separator that is not one character or not permitted by allowedCharacters, REPLACE with ALNUM which offers nothing to replace with, more than 8 padSegments, two padSegments on the same index, an index outside 0 to 128 or a width outside 1 to 128, or a padChar that is not one permitted character — or the rules name something we do not implement: an unknown property, or a case, allowedCharacters or onDisallowed value outside its set; retryable: no; next: fix the rule we name and resend. A rule that breaks a published length rather than contradicting another rule — a prefix or suffix past 16 characters — is a malformed request and comes back as the platform's validation error instead. SKU_EMPTY_RESULT — trigger: normalisation consumed the whole code, which happens when every character was a separator or outside the allowed set; retryable: no; next: widen rules.allowedCharacters, or send a code that carries at least one letter or digit.