Is the output valid TOML?

Yes. Tables use [section] headers, array-of-tables use [[section]], strings are double-quoted with escaping, and numbers, booleans, and dates render in their native TOML forms. The result parses with any spec-compliant TOML parser.

How does TOML represent data types?

TOML has explicit types: bare integers and floats, true/false booleans, double-quoted strings, RFC 3339 datetimes (offset or local), and arrays in square brackets. Unlike YAML, TOML does not infer string ambiguity, so all strings are quoted here for clarity.

Can I use this for Cargo.toml testing?

The Cargo preset emits a package section, a dependencies table, and a features array reflecting the real Cargo.toml layout. It is structurally representative for testing tooling, though you should validate against cargo before using it in a real crate.

What is array-of-tables?

Array-of-tables, written with double brackets like [[servers]], lets a TOML document repeat the same table structure multiple times, similar to a list of objects. Each [[servers]] block becomes one element of the servers array.

Mock TOML Generator — Gera Tools

Mock TOML Generator

TOML is the configuration format of choice for Rust’s Cargo, many Python tools (pyproject.toml), and a growing set of infrastructure utilities. Its strength is an unambiguous, explicitly typed syntax. When you build or test a TOML parser or a config-driven feature, you need valid sample documents that exercise tables, arrays, and the various scalar types. This tool generates them.

How it works

The generator serializes a structured value into TOML. Top-level scalars are emitted first, then named tables appear under [section] headers, and repeated structures use the array-of-tables form [[section]], where each block becomes one array element.

Type rendering follows the TOML spec exactly: integers and floats are bare, booleans render as true/false, datetimes use the RFC 3339 form, arrays use square brackets, and strings are double-quoted with backslash and quote escaping. Because TOML does not infer string ambiguity the way YAML does, every string is quoted, which keeps the output unambiguous and parser-safe. A generic preset and a Cargo.toml-style preset shape the document.

Tips and notes

Validate the output with a TOML parser (for example toml in Python or toml::from_str in Rust); it should parse cleanly.
The Cargo preset is structurally faithful but not validated by cargo, so confirm it before dropping it into a real crate.
Datetimes use RFC 3339, which is the only datetime form TOML accepts.
Increase the array-of-tables count to test how a parser handles many repeated sections.