Text Converter Tools
Evidence-backed workflow test

Case Conversion Edge Cases: A 16-Sample Determinism Test

Generated outputs for sentence/title/camel/Pascal/snake/kebab/upper conversions covering acronyms, brands, surnames, apostrophes, hyphens, numbers, and non-Latin text.

Question
Where is automatic case conversion deterministic yet still semantically wrong for names, brands, and acronyms?
Samples
16 fixtures
Generated via core
16
Manual / limits
0
Published
Modified
Author
Dionis Ceban
Method
Sixteen inputs run through named core functions (toSentenceCase, toTitleCase, toCamelCase, toPascalCase, toSnakeCase, toKebabCase, toUppercase). Outputs are generated—not hand-typed.

Why this test matters

Deterministic transforms still mangle NASA, iPhone, and McDonald-style names. Reviewers need concrete before/after pairs, not slogans.

Tools under test

Result summary

16 of 16 fixtures were executed through assets/js/tools-src/core.js. 0 entries are labeled manual review or limitation without inventing a transform result.

Full test matrix (16 samples)
IDCaseInputOperationObservedStatus
case-sentence-01 Sentence case basic hello WORLD toSentenceCase Hello world Pass
case-title-02 Title case stop-words the art of the deal toTitleCase The Art Of The Deal Pass
case-acronym-03 Acronym risk in title case NASA launch update toTitleCase Nasa Launch Update Pass
case-brand-04 Mixed-case brand iPhone release notes toTitleCase Iphone Release Notes Pass
case-surname-05 Surname McDonald mcdonald and o’neil toTitleCase Mcdonald And O’Neil Pass
case-apostrophe-06 Apostrophe word it's a writer's tool toTitleCase It's A Writer's Tool Pass
case-hyphen-07 Hyphenated words state-of-the-art design toTitleCase State-Of-The-Art Design Pass
case-punct-08 Sentence punctuation wait. WHAT? now… go! toSentenceCase Wait. What? Now… Go! Pass
case-camel-09 to camelCase customer account id toCamelCase customerAccountId Pass
case-pascal-10 to PascalCase customer account id toPascalCase CustomerAccountId Pass
case-snake-11 to snake_case Customer Account ID toSnakeCase customer_account_id Pass
case-kebab-12 to kebab-case Customer Account ID toKebabCase customer-account-id Pass
case-numbers-13 Numbers retained iso 9001 audit notes toTitleCase Iso 9001 Audit Notes Pass
case-cyrillic-14 Non-Latin script привет мир toTitleCase Привет Мир Pass
case-ws-15 Whitespace variations multi space path toCamelCase multiSpacePath Pass
case-upper-16 UPPERCASE Already Mixed toUppercase ALREADY MIXED Pass

Edge cases and failures

Title case lowercases stop-words mid-phrase but will also reshape acronyms and camel brands unless you intervene.

Conclusion

Trust the transform for mechanical formats (camel/snake/kebab); always re-check acronyms, product brands, and particle surnames after title/sentence case.

Limitations

  • No proper-noun dictionary or brand allowlist.
  • Apostrophe and hyphen handling follows the core regex, not style-manual exceptions.
  • Non-Latin casing depends on Unicode case mapping in the JavaScript engine.

Reproducibility

Re-run npm run guides:evidence and diff expected-results.json. Each fixture names the exact operation used.

Downloadable evidence

Related experiments

All guides