fusion

fusion is CLI tool to merge JSON, YAML or TOML files.

Installation

Download from the Releases page and put it somewhere in your $PATH.

Usage

Merge YAML files together with:

❯ fusion yaml file1.yml file2.yml ... fileN.yml -o result.yml

The same goes for JSON or TOML files, simply use the appropriate sub-command. E.g.

❯ fusion json file1.json file2.json ... fileN.json -o result.json

Note that since YAML is a superset of JSON, merging YAML and JSON files into YAML is also possible:

❯ fusion yaml file1.yml file2.json ... fileN.yml -o result.yml

Versioning

The versioning is done using semver.

When a new release must be performed, use mroth/bump to create a Git tag and the corresponding Github release, then, once pushed, the Goreleaser Github Action workflow will create the binaries.

The version can be checked with

❯ fusion version

Merging semantics

Fusion is based on gookit/config, itself based on imdario/mergo. Therefore, merge rules are the one implemented by Mergo.

Single key/value

Only the last value is retained. For example:

❯ cat file1.yml
key1: val1

❯ cat file2.yml
key1: val2

❯ fusion yaml file1.yml file2.yml -o res.yml && cat res.yml
key1: val2

Lists

Just like single values, only the last value of conflicting lists is retained. For example:

❯ cat file1.yml
list1:
  - val11
  - val12

❯ cat file2.yml
list1:
  - val21
  - val22

❯ fusion yaml file1.yml file2.yml -o res.yml && cat res.yml
list1:
  - val21
  - val22

Maps

Maps are merged together, keeping the last value for conflicting keys. For example:

❯ cat file1.yml
map1:
  key1: val11
  key2: val12

❯ cat file2.yml
map1:
  key1: val21
  key3: val23

❯ fusion yaml file1.yml file2.yml -o res.yml && cat res.yml
map1:
  key1: val21
  key2: val12
  key3: val23