community.general/test/integration/targets/environment/test_environment.yml

- hosts: testhost
  vars:
    - test1:
        key1: val1
  environment:
    PATH: '{{ansible_env.PATH + ":/lola"}}'
    lola: 'ido'
  tasks:
    - name: ensure special case with ansible_env is skipped but others still work
      assert:
        that:
            - lookup('env', 'PATH') == ansible_env.PATH
            - "'/lola' not in ansible_env.PATH"
            - ansible_env.lola == 'ido'

    - name: check that envvar does not exist
      shell: echo $key1
      register: test_env

    - name: assert no val in stdout
      assert:
        that:
            - '"val1" not in test_env.stdout_lines'

    - name: check that envvar does exist
      shell: echo $key1
      environment: "{{test1}}"
      register: test_env2

    - name: assert val1 in stdout
      assert:
        that:
            - '"val1" in test_env2.stdout_lines'

- hosts: testhost
  vars:
    - test1:
        key1: val1
    - test2:
        key1: not1
        other1: val2
  environment: "{{test1}}"
  tasks:
    - name: check that play envvar does exist
      shell: echo $key1
      register: test_env3

    - name: assert val1 in stdout
      assert:
        that:
            - '"val1" in test_env3.stdout_lines'

    - name: check that task envvar does exist
      shell: echo $key1; echo $other1
      register: test_env4
      environment: "{{test2}}"

    - name: assert all vars appear as expected
      assert:
        that:
            - '"val1" not in test_env4.stdout_lines'
            - '"not1" in test_env4.stdout_lines'
            - '"val2" in test_env4.stdout_lines'

    - block:
        - name: check that task envvar does exist in block
          shell: echo $key1; echo $other1
          register: test_env5

        - name: assert all vars appear as expected in block
          assert:
            that:
                - '"val1" not in test_env5.stdout_lines'
                - '"not1" in test_env5.stdout_lines'
                - '"val2" in test_env5.stdout_lines'
      environment: "{{test2}}"

- name: test setting environment while using loops
  hosts: testhost
  environment:
    foo: outer
  tasks:
    - name: verify foo==outer
      command: /bin/echo $foo
      loop:
        - 1
      register: test_foo

    - name: assert foo==outer
      assert:
        that:
          - "{{ test_foo.results[0].stdout == 'outer' }}"

    - name: set environment on a task
      environment:
        foo: in_task
      command: /bin/echo $foo
      loop:
        - 1
      register: test_foo

    - name: assert foo==in_task
      assert:
        that:
          - "test_foo.results[0].stdout == 'in_task'"

    - name: test that the outer env var is set appropriately still
      command: /bin/echo $foo
      loop:
        - 1
      register: test_foo

    - name: assert foo==outer
      assert:
        that:
          - "{{ test_foo.results[0].stdout == 'outer' }}"

    - name: set environment on a block
      environment:
        foo: in_block
      block:
        - name: test the environment is set in the block
          command: /bin/echo $foo
          loop:
            - 1
          register: test_foo

        - name: assert foo==in_block
          assert:
            that:
              - "test_foo.results[0].stdout == 'in_block'"

        - name: test setting environment in a task inside a block
          environment:
            foo: in_block_in_task
          command: /bin/echo $foo
          loop:
            - 1
          register: test_foo

        - name: assert foo==in_block_in_task
          assert:
            that:
              - "test_foo.results[0].stdout == 'in_block_in_task'"

        - name: test the environment var is set to the parent value
          command: /bin/echo $foo
          loop:
            - 1
          register: test_foo

        - name: assert foo==in_block
          assert:
            that:
              - "test_foo.results[0].stdout == 'in_block'"

    - name: test the env var foo has the initial value
      command: /bin/echo $foo
      loop:
        - 1
      register: test_foo

    - name: assert foo==outer
      assert:
        that:
          - "{{ test_foo.results[0].stdout == 'outer' }}"