Best AI Developer Generators in 2026: Regex, SQL, Excel Formulas, Unit Tests, Commit Messages and Code Review (With Live Examples)

The best AI developer generators in 2026 are not separate apps, they are well-structured prompts you can paste into Claude, ChatGPT, Gemini or Copilot: a regex generator that ships test cases, a SQL generator that reads your schema, an Excel formula generator that explains itself, a unit test generator that covers boundaries, a commit message generator that follows Conventional Commits, and a code review generator that works from a checklist. This guide gives you all six, each with a copy-paste prompt and a worked example so you can see what good output looks like before you run it.

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When a one-off generator beats an IDE assistant

You probably already have an inline assistant in your editor. It is good at the next line, the next function, the obvious refactor. It is weaker at anything that needs a fixed procedure, because it optimises for speed and context, not for method.

A generator prompt wins in four situations:

  • The task has a checklist. Code review, test coverage and commit hygiene all have rules. An inline assistant will follow them sometimes. A prompt with the rules written down follows them every time.
  • You want the reasoning, not just the answer. A regex or a formula you cannot explain will bite you in six months. A generator that outputs the explanation alongside the result is a small amount of extra reading now for a lot less debugging later.
  • The input lives outside the editor. A stakeholder's plain-English question that needs a SQL answer, a spreadsheet request from finance, a diff summary you are pasting from a ticket. None of that is in your IDE buffer.
  • You want the same quality on every model. Prompts travel. If your team is split between Claude Code and Copilot, a shared prompt file gives everyone the same output shape.

The IDE assistant still wins for tight loops: autocomplete, renaming, quick fixes where the context is the file you are looking at. Use both. Keep the generators for the tasks where a fixed method matters, and keep them somewhere you can reach in one command (more on that at the end).

1. Regex generator

What good output looks like

A good regex generator returns three things: the pattern, a line-by-line explanation of what each group does, and a set of test strings with expected pass or fail results. If it also tells you which flavour of regex it assumed (PCRE, JavaScript, Python re, POSIX), even better. Anything less is a pattern you have to reverse-engineer yourself.

Prompt 1: Regex with tests
Write a regular expression for [describe what should match, e.g. US phone numbers in the form (555) 123-4567 or 555-123-4567]. Target flavour: [JavaScript / Python / PCRE]. Return: (1) the pattern on its own line, (2) a plain-English explanation of every group and quantifier, (3) six test strings, three that should match and three that should not, with the expected result for each. Do not use lookbehind unless I say the flavour supports it.

Worked example

Input: match a semantic version like 1.4.2 or 2.0.0-beta.1, JavaScript flavour

Pattern:
^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([0-9A-Za-z.-]+))?$

Explanation:
^ ... $            anchor the whole string, no partial matches
(0|[1-9]\d*)       a number with no leading zero (0 alone is allowed)
\.                 literal dot between major, minor, patch
(?:-([0-9A-Za-z.-]+))?  optional pre-release tag after a hyphen

Tests:
1.4.2          match
2.0.0-beta.1   match
0.0.1          match
01.2.3         no match (leading zero)
1.2            no match (patch missing)
1.2.3.4        no match (extra segment)

2. SQL generator

What good output looks like

The single biggest failure of SQL prompts is invented column names. A good generator is schema-aware: you give it the tables, it uses only those, and it tells you when the question cannot be answered from what you supplied. It also names the dialect, because DATE_TRUNC, LIMIT and string concatenation differ between Postgres, MySQL, SQL Server and BigQuery. If you want a form-based version, the SQL query builder page walks through the same steps.

Prompt 2: Schema-aware SELECT
You are writing [PostgreSQL / MySQL / BigQuery] SQL. Here is the schema: [paste CREATE TABLE statements or table: column list]. Question: [plain-English question, e.g. which customers placed more than 3 orders in the last 90 days, with their total spend]. Rules: use only the columns above; if you need a column that does not exist, say so instead of inventing it; return the query, then a two-sentence explanation of the joins and filters; note any assumption about time zones or null handling.

Worked example

Schema:
customers(id, email, created_at)
orders(id, customer_id, total_cents, placed_at, status)

Question: customers with more than 3 completed orders in the last 90 days,
with their total spend, biggest spenders first. Postgres.

SELECT c.id,
       c.email,
       COUNT(o.id)            AS order_count,
       SUM(o.total_cents)/100.0 AS total_spend
FROM customers c
JOIN orders o ON o.customer_id = c.id
WHERE o.status = 'completed'
  AND o.placed_at >= NOW() - INTERVAL '90 days'
GROUP BY c.id, c.email
HAVING COUNT(o.id) > 3
ORDER BY total_spend DESC;

Explanation: inner join keeps only customers with at least one order; the
WHERE clause filters to completed orders in the window before grouping, so
the HAVING count reflects the window only. Assumes placed_at is stored in
UTC and total_cents is never null.

3. Excel and Google Sheets formula generator

What good output looks like

A useful Excel formula generator asks for, or infers, the exact cell ranges and returns a formula you can paste without editing, plus a plain-English reading of it and one note on what breaks it (blank cells, text stored as numbers, mismatched ranges). It should also say whether the formula is Excel-only, Sheets-only or works in both, since FILTER, LET and ARRAYFORMULA are not universal. There is a page-based version at the Excel formula generator.

Prompt 3: Plain English to formula
I am working in [Excel 365 / Google Sheets]. Column layout: [e.g. A = date, B = region, C = amount, rows 2 to 500]. I want a formula in [cell] that [plain-English request]. Return the formula ready to paste, then explain each function in one line each, then list one or two conditions under which it returns an error or a wrong answer and how to guard against them.

Worked example

Input: Google Sheets. A = date, B = region, C = amount (rows 2:500).
In F2, total amount for region "EMEA" in the current month.

Formula:
=SUMIFS(C2:C500, B2:B500, "EMEA", A2:A500, ">="&EOMONTH(TODAY(),-1)+1,
        A2:A500, "<="&EOMONTH(TODAY(),0))

Explanation:
SUMIFS      sums C where every paired condition is true
B = "EMEA"  region filter, case-insensitive in Sheets
A >= first of month   EOMONTH(TODAY(),-1)+1 is the 1st of this month
A <= last of month    EOMONTH(TODAY(),0) is the last day of this month

Breaks when: dates in A are text, not real dates (wrap with DATEVALUE or
fix the column); region has trailing spaces (use TRIM in a helper column).
Works in both Excel and Sheets.

4. Unit test generator

What good output looks like

A unit test generator earns its place when it covers three categories on purpose: the happy path, the boundaries (empty, zero, maximum, off-by-one), and the error path (bad input, thrown exceptions, rejected promises). It should name the framework and produce tests that run without edits. Ask for a one-line reason next to each test so the reviewer knows what it protects. For broader QA planning beyond unit tests, the free test case generator page covers manual and integration cases, and Mira - QA Engineer AI Skill ($29) is the persona version for teams that want the same coverage discipline in every session.

Prompt 4: Three-category tests
Write unit tests for the following function using [Jest / pytest / JUnit / Go testing]. Cover three groups, labelled in the code: happy path (2 to 3 tests), boundaries (empty input, zero, largest reasonable value, off-by-one), and errors (invalid types, thrown or returned errors). Put a one-line comment above each test saying what bug it would catch. Do not mock anything unless the function has an external dependency. Function: [paste code]

Worked example

Function under test (TypeScript):
export function chunk<T>(arr: T[], size: number): T[][] {
  if (size <= 0) throw new RangeError("size must be positive");
  const out: T[][] = [];
  for (let i = 0; i < arr.length; i += size) out.push(arr.slice(i, i + size));
  return out;
}

Tests (Jest):
describe("chunk", () => {
  // happy path
  it("splits evenly", () => expect(chunk([1,2,3,4], 2)).toEqual([[1,2],[3,4]]));
  // happy path: last chunk shorter
  it("keeps the remainder", () => expect(chunk([1,2,3], 2)).toEqual([[1,2],[3]]));

  // boundary: empty input returns empty, not [[]]
  it("returns [] for empty array", () => expect(chunk([], 3)).toEqual([]));
  // boundary: size larger than array yields one chunk
  it("one chunk when size > length", () => expect(chunk([1,2], 5)).toEqual([[1,2]]));
  // boundary: size 1 yields singletons
  it("size 1", () => expect(chunk([1,2], 1)).toEqual([[1],[2]]));

  // error: zero size would loop forever without the guard
  it("throws on size 0", () => expect(() => chunk([1], 0)).toThrow(RangeError));
  // error: negative size
  it("throws on negative size", () => expect(() => chunk([1], -2)).toThrow());
});

5. Commit message generator

What good output looks like

A commit message generator should produce Conventional Commits: a type (feat, fix, refactor, chore, docs, test), an optional scope, a subject under 72 characters in the imperative, a body that explains why rather than what, and a footer for breaking changes or issue references. It should refuse to write fix stuff. Feed it a diff summary or the actual git diff --stat output. The same approach at PR level is on the free PR description generator page.

Prompt 5: Conventional commit from diff
Write a Conventional Commits message for this change. Format: type(scope): subject, blank line, body of 1 to 3 sentences explaining why the change was made and any behaviour that differs, blank line, footer with BREAKING CHANGE: or Refs: if applicable. Subject in imperative mood, under 72 characters, no trailing period. If the diff mixes unrelated concerns, tell me to split the commit and propose two messages. Diff summary: [paste git diff --stat and a sentence on the intent]

Worked example

Diff summary:
 src/auth/session.ts        | 18 +++++---
 src/auth/session.test.ts   | 24 ++++++++++
 docs/config.md             |  3 +
Intent: session tokens now expire after 12 hours instead of never, and the
value is read from SESSION_TTL_HOURS. Old tokens without an expiry claim are
rejected on next request.

Output:
feat(auth): expire session tokens after configurable TTL

Sessions previously never expired, which kept stale tokens valid after
password resets. Tokens now carry an exp claim set from SESSION_TTL_HOURS
(default 12) and are rejected once past it.

BREAKING CHANGE: tokens issued before this release have no exp claim and
will be rejected; users must sign in again.
Refs: #482

6. Code review generator

What good output looks like

The difference between a shallow and a useful code review AI is a checklist. Without one, the model comments on formatting and stops. With one, it walks correctness, edge cases, security, error handling, naming and tests in order, marks each item as pass or issue, and quotes the line it is talking about. Good output also ranks findings by severity so you fix the real problem first. Albert - AI Code Review Agent ($32) and Soren - Code Auditor AI Skill ($29) are two ready-made checklists if you would rather not maintain your own; Soren leans toward security and dependency audits, Albert toward day-to-day PR review.

Prompt 6: Checklist review
Review the following code as a senior engineer. Go through this checklist in order and report pass or issue for each: (1) correctness against the stated intent, (2) edge cases and null or empty input, (3) security (injection, secrets, unsafe deserialisation), (4) error handling and logging, (5) naming and readability, (6) missing tests. For each issue quote the exact line, explain the failure scenario in one sentence, and give the fix. Rank issues blocker / should fix / nit. Intent: [what the code should do]. Code: [paste snippet]

Worked example

Intent: return a user's public profile by id, or 404.

 1  app.get("/users/:id", async (req, res) => {
 2    const id = req.params.id;
 3    const rows = await db.query(
 4      "SELECT * FROM users WHERE id = " + id
 5    );
 6    const user = rows[0];
 7    res.json({
 8      id: user.id,
 9      name: user.name,
10      email: user.email,
11      password_hash: user.password_hash,
12      created: user.created_at
13    });
14  });

Review:
1 Correctness      ISSUE (should fix) line 6-7: no 404 branch; a missing id
                   returns a 500 from reading user.id on undefined.
2 Edge cases       ISSUE (should fix) line 2: id is never validated as an
                   integer; "abc" reaches the database.
3 Security         BLOCKER line 4: string-concatenated SQL, injectable.
                   Use a parameterised query: db.query("... WHERE id = $1", [id]).
                   BLOCKER line 11: password_hash is returned to the client.
                   Remove it; select only the public columns.
4 Error handling   ISSUE (should fix) line 3: no try/catch; a db error crashes
                   the handler with no log line.
5 Naming           PASS
6 Tests            ISSUE (nit): none provided; add 200, 404 and non-numeric id.

Where to keep these in Claude Code

Six prompts in a notes app is six copy-paste steps. In Claude Code you can save each one as a skill: a markdown file with a name, a description of when to use it, and the prompt body. Then /review, /tests or /commit runs the full checklist against whatever is in your working tree, and the same file works when a teammate loads it into ChatGPT or Gemini. The Claude Code skills guide covers where the files live, how to install them and what a well-written one looks like.

If you want a starting set rather than writing your own, Tech & Dev Prompt Library ($21) is a collection of developer prompts in that format, Elena - Data Engineer AI Skill ($29) is the persona to reach for on the SQL and pipeline side, and the wider Claude Code skills collection has the rest. Every skill is a one-time purchase with a 30-day money-back guarantee.

Frequently asked questions

Is an AI regex generator reliable enough for production code?

It is reliable when you make it show its work. Ask for the pattern, a plain-English explanation of each part, and at least five test strings with expected results. Then run those tests yourself. A regex you cannot explain is a regex you cannot maintain, whoever wrote it.

How do I stop SQL prompts from inventing tables and columns?

Paste the schema. Give the model the CREATE TABLE statements or a short list of tables and columns, and tell it to use only what you provided. Ask it to flag any column it needs but cannot find. Without a schema, any SQL generator is guessing names, and it will guess confidently.

Do these generators work in ChatGPT, Gemini and Copilot as well as Claude?

Yes. Every prompt in this article is model-agnostic plain text. The KissMySkills skills are .md files that load into Claude and Claude Code, ChatGPT custom GPTs, Gemini Gems and Copilot. The output quality varies a little between models, but the prompt structure carries over.

What is the difference between a unit test generator and just asking for tests?

The framing. Asking for tests usually gets you three happy-path cases that all pass. A test generator prompt names the three categories it must cover (happy path, boundaries, error handling), asks for the reasoning behind each case, and tells the model which test framework you use so the output runs without edits.

Can I get a refund if a skill does not fit my workflow?

Yes. Every skill on KissMySkills has a 30-day money-back guarantee, no questions asked. Skills are one-time purchases with no subscription.

The bottom line

Generators beat IDE assistants when the task has a method: regex with tests, SQL against a real schema, formulas that explain themselves, tests in three categories, commits that say why, reviews that follow a checklist. Paste the six prompts above, run the worked examples against your own code to check the shape, and then save the ones you use weekly as skills so they are one command away.

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