fledge-plugin-json

JSON toolkit plugin for fledge -- format, minify, validate, query, diff, and inspect JSON from the terminal.

Install

fledge plugins install corvid-agent/fledge-plugin-json

Commands

fmt -- Format / pretty-print

# Pretty-print a file with default 2-space indent
fledge json fmt data.json

# Custom indent width
fledge json fmt data.json --indent 4

# Sort keys alphabetically
fledge json fmt data.json --sort-keys

# Format in place (overwrites the file)
fledge json fmt data.json --in-place

# Read from stdin
cat data.json | fledge json fmt

min -- Minify

# Remove all whitespace
fledge json min data.json

# From stdin
cat data.json | fledge json min

validate -- Validate syntax

Exits with code 0 for valid JSON, 1 for invalid.

# Human-readable output
fledge json validate config.json
# => config.json: valid JSON

# Machine-readable output
fledge json validate config.json --json
# => {"valid":true,"file":"config.json"}

# From stdin
echo '{"ok": true}' | fledge json validate

query -- Dot-path query

Extract values using dot-path syntax: .key, .nested.key, .array[0], .array[0].name.

# Query a nested key
fledge json query .name data.json
# => "alice"

# Raw string output (no quotes)
fledge json query .name data.json --raw
# => alice

# Array access
fledge json query .items[0] data.json

# Combined access
fledge json query .users[1].email data.json

diff -- Semantic diff

Compare two JSON files semantically (ignoring formatting). Shows added, removed, and changed keys.

# Human-readable diff
fledge json diff a.json b.json
# + .newKey: "value"
# - .removedKey: 42
# ~ .changedKey: "old" -> "new"

# Machine-readable output
fledge json diff a.json b.json --json

type -- Show top-level type

fledge json type data.json
# => object (3 keys)

fledge json type list.json
# => array (length 5)

# Machine-readable output
echo '42' | fledge json type --json
# => {"type":"number"}

Development

Requires Swift 6.0+.

swift build
swift test

Architecture

The codebase is split into two targets:

• JsonLib (Sources/JsonLib/) -- pure functions for JSON serialization, querying, diffing, type inspection, and argument parsing. No I/O or process exit calls.
• fledge-json (Sources/main.swift) -- CLI entry point, I/O helpers, and command dispatch. Imports JsonLib.

Tests in Tests/JsonTests.swift cover all public functions in JsonLib.

License

MIT