templx

Lightweight CLI to render Handlebars templates with options derived from CLI flags.

Usage

npx templx format <template.hbs> [flags] [-]

• Command: only format is supported.
• Template: path to a Handlebars file.
• Flags: become template options (see mapping below).
• - (single hyphen) as a positional means: read JSON options from stdin.

Flags ➜ options mapping

• Flags become keys on the options object by flag name, without dashes.
  • Parsing collects values as arrays, then a single value is coerced to a string.
  • --name Alice ➜ { name: "Alice" }
  • --name=Alice is equivalent.
• Repeating a flag accumulates values:
  • --color red --color blue ➜ { color: ["red", "blue"] }
• Pending option consumption: if a flag has no inline value, the next positional token becomes its value—even if it is -.
• Option terminator -- stops parsing further tokens.

Notes:

• Single-occurrence flags become strings; repeated flags remain arrays. Write templates normally, e.g. {{name}}.
• Stdin JSON values are left as-is; only CLI flags are coerced.
• Handlebars runs in strict mode: missing variables cause an error.

Stdin JSON (-)

Provide a single - positional to read a JSON object from stdin. The JSON object is intelligently merged with CLI flags. Stdin values are not coerced; only flags are.

# stdin only
echo '{"name":"Bob","colors":["green"]}' \
  | npx templx format template.hbs -

# stdin + flags merge
echo '{"name":"Bob","colors":["green"],"meta":{"a":1}}' \
  | npx templx format template.hbs - --name Carol --colors yellow --meta.b 2

Merge rules:

• At most one - is accepted as a free positional.
• If a flag is waiting for a value, - is consumed as that value (no stdin mode in that case).
• Stdin must be a top-level JSON object.
• Intelligent merge between stdin (left) and CLI (right):
  • Objects: deep-merged
  • Arrays: concatenated (stdin first, then CLI)
  • Mixed array/scalar: scalar promoted to array and concatenated
  • Scalars: CLI overrides stdin

Examples

Template (template.hbs):

Hello {{name}}!
Colors: {{#each colors}}{{this}}{{#unless @last}}, {{/unless}}{{/each}}.

Run:

npx templx format template.hbs --name Alice --colors red --colors blue
# => Hello Alice!
# => Colors: red, blue.

With stdin merge:

echo '{"name":"Bob","colors":["green"],"meta":{"a":1}}' \
  | npx templx format hi.hbs - --name Carol --colors yellow --meta.b 2
# => Hello Carol!
# => Colors: green, yellow.