esphome/tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml

esphome:
  name: test

substitutions:
  substituted: 99
  var1: "1"
  var2: "2"
  var21: "79"
  value: 33
  values: 44
  position:
    x: 79
    y: 82
  a: 10
  b: 20

# The following key is only used by the test framework
# to simulate command line substitutions
command_line_substitutions:
  a: 15

test_list:
  - "$var1"
  - "${var1}"
  - $var1
  - ${var1}
  - "Values: $var1 ${var2}"
  - "Value: ${var2${var1}}"
  - "$var1 + $var2"
  - "${ var1 } * ${ var2 }"
  - "Undefined var: ${undefined_var}"
  - ${undefined_var}
  - $undefined_var
  - ${ undefined_var }
  - key${var1}: 1
    key${var2}: 2
  - !literal Literal $values ${are not substituted}
  - !literal ["list $value", "${is not}", "${substituted}"]
  - !literal {"$dictionary": "$value", "${is not}": "${substituted}"}
  - |- # Test parsing things that look like a python set of sets when rendered:
    {{{ "x", "${ position.x }"}, { "y", "${ position.y }"}}}
  - ${ '{{{"AA"}}}' }
  - ${ '"HELLO"' }
  - '{ ${position.x}, ${position.y} }'
  - a: ${a} should be 15, overridden from command line
    b: ${b} should stay as 20, not overridden

  # Test merging lists when substituted keys resolve to an existing key
  - ${ "aa" }: [1, 2, 3]
    ${ "a" + "a" }: [4, 5, 6]
    ${ "bb" }: [7, 8, 9]

  # Test merging dicts when substituted keys resolve to an existing key
  - ${ "aa" }: {"x": 1, "y": 2}
    ${ "a" + "a" }: {"y": 3, "z": 4}
    ${ "bb" }: {"w": 5}