The go.jetpack.io/hujson package implements an extension of standard JSON that is easier for humans to write and modify. It's based on Tailscale's corresponding HuJSON library but allows for some additional syntax.

Example:

{
    /* Block comments and multiline strings */
    multi: `
      This is a
      multiline string
    `,

    bar: "baz", // Line comments are allowed and unquoted keys
    foo: "bar", // Trailing commas are allowed too
}

Jetpack.io's HuJSON format permits the following additions over standard JSON:

C-style line comments and block comments can be intermixed with whitespace.

Example:

{
    // This is a line comment
    "foo": "bar", /* This is a block comment */
    "baz": "quux"
}

Trailing commas after the last member/element in an object/array are allowed.

Examples:

{
    "foo": "bar", // It's ok to have a comma in the last element
}

As a result, you can comment out the last entry in an object or array, and the commas still parse correctly:

{
    "foo": "bar",
    // "baz": "quux"
}

Multiline strings are allowed. Multiline strings use JavaScript's template strings syntax, and are delimited with a backtick (`).

They are particularly useful for writing long strings that contain newlines.

Example:

{
    "foo": `This is a multiline string
    that contains a newline`,

    // This is an inline bash script:
    "script": `
        #!/bin/bash
        echo "Hello, world!"
    `
}

The key for an object can be written without quotes if it starts with a letter (a-z, A-Z) and is followed by letters, numeric digits, or underscores. Javscript, and Typescript already allow for unquoted keys (but standard JSON does not)

Example:

{
    foo: "bar",
    baz_quux: "quuz"
}