Init

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*.cr]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

.gitignore

@@ -0,0 +1,9 @@
+/docs/
+/lib/
+/bin/
+/.shards/
+*.dwarf
+
+# Libraries don't need dependency lock
+# Dependencies will be locked in applications that use them
+/shard.lock

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 Dominic Grimm <dominic.grimm@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,49 @@
+# senf
+
+A safe environment variable requester.
+Should not be used in any kind of production environment.
+
+## Installation
+
+1. Add the dependency to your `shard.yml`:
+
+   ```yaml
+   dependencies:
+     senf:
+       git: https://git.dergrimm.net/dergrimm/senf.git
+   ```
+
+2. Run `shards install`
+
+## Usage
+
+```crystal
+require "senf"
+
+SAFE_ENV = Senf::SafeEnv.new([
+  "TEST_1",
+  "TEST_2"
+])
+
+SAFE_ENV << "TEST_3"
+
+p! SAFE_ENV["TEST_1"],
+  SAFE_ENV["TEST_2"],
+  SAFE_ENV["TEST_3"]
+```
+
+## Development
+
+TODO: Write development instructions here
+
+## Contributing
+
+1. Fork it
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create a new Pull Request
+
+## Contributors
+
+- [Dominic Grimm](https://git.dergrimm.net/dergrimm) - creator and maintainer

shard.yml

@@ -0,0 +1,9 @@
+name: senf
+version: 0.1.0
+
+authors:
+  - Dominic Grimm <dominic.grimm@gmail.com>
+
+crystal: 1.3.0
+
+license: MIT

src/senf.cr

@@ -0,0 +1,38 @@
+module Senf
+  VERSION = {{ `shards version`.stringify.chomp.downcase }}
+
+  class SafeEnv
+    private property keys
+
+    def initialize(@keys = {} of String => String?)
+    end
+
+    def initialize(keys : Array(String))
+      @keys = {} of String => String?
+      keys.each { |k| self.<< k }
+    end
+
+    def <<(key : String) : self
+      @keys[key] = ENV[key]?
+
+      self
+    end
+
+    def []?(key : String) : String?
+      if @keys.has_key?(key)
+        @keys[key]?
+      end
+    end
+
+    def [](key : String) : String
+      if @keys.has_key?(key)
+        val = @keys[key]?
+        raise "ENV[#{key}] is nil" unless val
+
+        val
+      else
+        raise "No such key: #{key}"
+      end
+    end
+  end
+end