jsonfile.star¶

Read and edit any JSON file, keeping key order and indentation.

For files such as renovate.json, tsconfig.json without comments, .eslintrc.json and composer.json. Keys are addressed with dots, such as compilerOptions.strict; for a key that itself contains dots or slashes, pass the path as a list, such as ["require", "laravel/framework"]. Files with comments (JSONC) can't be decoded and fail the run.

load("@fleet//jsonfile.star", "read", "write", "get", "set", "delete")

Function	What it does
`read`	Reads a JSON file into a value whose dict keys keep the file's order.
`write`	Writes a value as JSON in the layout the file already has.
`get`	Reads a value by dotted key path.
`set`	Sets a value by dotted key path, adding missing objects on the way.
`delete`	Removes a key by dotted key path.

read¶

read(repo, path, default = None)

Reads a JSON file into a value whose dict keys keep the file's order.

Arguments

Name	Description
`repo`	The repo passed to `change(repo)`.
`path`	The JSON file, relative to the repo root.
`default`	What to return when the file does not exist; without it, a missing file fails the run.

Returns: The decoded value.

Example

read(repo, "renovate.json")["extends"]
# returns ["config:base"]

Before

renovate.json

{"extends": ["config:base"], "schedule": ["weekly"]}

Source

write¶

write(repo, path, data)

Writes a value as JSON in the layout the file already has.

Values that didn't change keep their exact text, so a one-key edit is a one-line diff. Changed and new values follow the indentation and separators around them, and new lists of plain values are written on one line when the file already writes lists that way. A new file gets two spaces. Output ends with a newline.

Arguments

Name	Description
`repo`	The repo passed to `change(repo)`.
`path`	The JSON file, relative to the repo root.
`data`	The value to write, usually from `read`.

Returns: True when the file changed.

Example

config = read(repo, ".eslintrc.json")
config["extends"] = ["eslint:recommended"]
write(repo, ".eslintrc.json", config)
# returns True

BeforeAfter

.eslintrc.json

{
    "root": true
}

.eslintrc.json

{
    "root": true,
    "extends": [
        "eslint:recommended"
    ]
}

Source

get¶

get(repo, path, key, default = None)

Reads a value by dotted key path.

Arguments

Name	Description
`repo`	The repo passed to `change(repo)`.
`path`	The JSON file, relative to the repo root.
`key`	The dotted key path, such as `compilerOptions.strict`.
`default`	What to return when the file or key is missing.

Returns: The value, or default.

Example

get(repo, "tsconfig.json", "compilerOptions.target")
# returns "ES2020"

Before

tsconfig.json

{"compilerOptions": {"strict": false, "target": "ES2020"}}

Source

set¶

set(repo, path, key, value)

Sets a value by dotted key path, adding missing objects on the way.

The file is created if needed. Existing keys keep their place; new keys go at the end of their object.

Arguments

Name	Description
`repo`	The repo passed to `change(repo)`.
`path`	The JSON file, relative to the repo root.
`key`	The dotted key path, such as `compilerOptions.strict`.
`value`	Any JSON value: string, number, boolean, None, list or dict.

Returns: True when the file changed.

Example

set(repo, "tsconfig.json", "compilerOptions.strict", True)
# returns True

BeforeAfter

tsconfig.json

{
  "compilerOptions": {
    "strict": false
  }
}

tsconfig.json

{
  "compilerOptions": {
    "strict": true
  }
}

Used in: renovate-preset

Source

delete¶

delete(repo, path, key)

Removes a key by dotted key path.

Arguments

Name	Description
`repo`	The repo passed to `change(repo)`.
`path`	The JSON file, relative to the repo root.
`key`	The dotted key path.

Returns: True when the file changed.

Example

delete(repo, "package.json", "scripts.postinstall")
# returns True

BeforeAfter

package.json

{
  "name": "web",
  "scripts": {
    "test": "jest",
    "postinstall": "husky install"
  }
}

package.json

{
  "name": "web",
  "scripts": {
    "test": "jest"
  }
}

Source