go-header

Go source code linter providing checks for license headers.

Installation

For installation you can simply use go get.

go install github.com/denis-tingaikin/go-header/cmd/go-header

Configuration

To configuring .go-header.yml linter you simply need to fill the next fields:

---
template: # expects header template string.
template-path: # expects path to file with license header string. 
values: # expects `const` or `regexp` node with values where values is a map string to string.
  const:
    key1: value1 # const value just checks equality. Note `key1` should be used in template string as {{ key1 }} or {{ KEY1 }}.
  regexp:
    key2: value2 # regexp value just checks regex match. The value should be a valid regexp pattern. Note `key2` should be used in template string as {{ key2 }} or {{ KEY2 }}.

Where values also can be used recursively. Example:

values:
  const:
    key1: "value" 
  regexp:
    key2: "{{key1}} value1" # Reads as regex pattern "value value1"

Bult-in values

• MOD-YEAR - Returns the year when the file was modified.
• MOD-YEAR-RANGE - Returns a year-range where the range starts from the year when the file was modified.
• YEAR - Expects current year. Example header value: 2020. Example of template using: {{YEAR}} or {{year}}.
• YEAR-RANGE - Expects any valid year interval or current year. Example header value: 2020 or 2000-2020. Example of template using: {{year-range}} or {{YEAR-RANGE}}.

Execution

go-header linter expects file paths on input. If you want to run go-header only on diff files, then you can use this command:

go-header $(git diff --name-only | grep -E '.*\.go')

Setup example

Step 1

Create configuration file .go-header.yml in the root of project.

---
values:
  const:
    MY COMPANY: mycompany.com
template: |
  {{ MY COMPANY }}
  SPDX-License-Identifier: Apache-2.0

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at:

  	  http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

Step 2

You are ready! Execute go-header ${PATH_TO_FILES} from the root of the project.