Pretty JSON Action for Mac

Overview

What Pretty JSON does

Validates JSON and formats it with two-space indentation without rewriting large numeric literals or duplicate keys.

Category	Developer Tools
Action type	JavaScript
Result	Replace or copy text
Internet	Not required

Example

Action and outcome

Pretty JSON example
Action	Outcome
Pretty JSONSelected text: {"name":"ActionClip","enabled":true}	{ "name": "ActionClip", "enabled": true }

Workflow

Use Pretty JSON

Follow these steps to format selected JSON with readable indentation with ActionClip.

Select the text you want to use.
Choose Pretty JSON from ActionClip.
Review the result, then replace the selection or copy the new text.

Before you add it

Requirements and privacy

Before you start: No setup required.
Your selected text: Runs locally in ActionClip’s JavaScript sandbox. Selected text does not leave your Mac.

Inspect before installing

Action configuration

The definition below is included so you can inspect how the action works before downloading it.

JavaScript definition

function run(selected_text) {
  const input = selected_text.trim();
  try {
    JSON.parse(input);
  } catch (error) {
    throw new Error("Invalid JSON: " + error.message);
  }

  let output = "";
  let depth = 0;
  let inString = false;
  let escaped = false;
  const indent = () => "  ".repeat(depth);
  const nextNonWhitespace = (start) => {
    for (let index = start; index < input.length; index += 1) {
      if (!/\s/.test(input[index])) return input[index];
    }
    return "";
  };

  for (let index = 0; index < input.length; index += 1) {
    const character = input[index];
    if (inString) {
      output += character;
      if (escaped) escaped = false;
      else if (character === "\\") escaped = true;
      else if (character === '"') inString = false;
      continue;
    }

    if (character === '"') {
      inString = true;
      output += character;
    } else if (character === "{" || character === "[") {
      output += character;
      const closing = character === "{" ? "}" : "]";
      if (nextNonWhitespace(index + 1) !== closing) {
        depth += 1;
        output += "\n" + indent();
      }
    } else if (character === "}" || character === "]") {
      const opening = character === "}" ? "{" : "[";
      let previous = output.length - 1;
      while (previous >= 0 && /\s/.test(output[previous])) previous -= 1;
      if (previous >= 0 && output[previous] !== opening) {
        depth = Math.max(0, depth - 1);
        output = output.replace(/\s+$/, "") + "\n" + indent();
      }
      output += character;
    } else if (character === ",") {
      output += ",\n" + indent();
    } else if (character === ":") {
      output += ": ";
    } else if (!/\s/.test(character)) {
      output += character;
    }
  }
  return output;
}