patch-dotenv

Patch a .env file in place, preserving the existing formatting.

pnpm add patch-dotenv

Why make this?

I have scripts that provide environment variables to my app, but I also wanted to allow manually setting variables in the same file.

CLI Commands

When using the CLI, keys are always converted to uppercase.

• set <file> <key> <value>: Sets a variable in the specified .env file.

patch-dotenv set .env my_key my_value

• unset <file> <key>: Unsets a variable in the specified .env file.

patch-dotenv unset .env my_key

• Aliases for unset: del, rm, delete, remove.

API Documentation

parse(content: string): Node[]

Parses a string into an array of Node objects, representing the structure of a .env file.

patch(content: string, patch: PatchCallback | Variables)

Parses the content, applies the changes defined in the patch argument, and returns the patched content. The patch argument can be either a callback function or a Variables object (representing the variables to set). If it's a callback, it receives a variables object (representing the variables in the .env file) and the nodes array.

patchFile(file: string, patch: PatchCallback | Variables)

Reads a file, patches its content using the patch function, and writes the patched content back to the file. The patch argument can be either a callback function or a Variables object (representing the variables to set).

stringify(node: Node)

Converts a Node object back into a string representation suitable for writing to a .env file.

Node Types

• Space: Represents an empty line.
• Comment: Represents a comment line (starting with #).
• Variable: Represents a variable assignment (e.g., KEY=value).

Other Types

• PatchCallback: Represents a callback function that receives a variables object and a nodes array.
• Variables: Represents a map of variable names to values.