NodeJS now supports --load-env=.env, so you don't need the dotenv package anymore. However, the two ways of reading .env files disagree on parsing. (I remember docker-compose parses .env files different to dotenv, too, but haven't re-tested it now.)

.env

VAR1
VAR2 = 
  VAR3 = "EGG BACON" "AND SPAM"
"VAR4"="BLUBB"
"VAR 4"=BLUBB
VAR5= "FOO BAR" # COMMENT
VAR6= FOO BAR # COMMNET

#VAR7=...

VAR8 = "FOO" "
BAR1=BAZ"

VAR9="FOO
BAR2=BAZ"

VAR10= "FOO BAR" BAZ BLA

11=111111

VAR12=#COMMENT
VAR13=TEXT#NO COMMENT
VAR14="#NO COMMNET"
VAR15= "#NO COMMNET" 
VAR16="double quoted backslash:\\double quote:\"single quote:\'newline:\ntab:\tbackspace:\bformfeed:\fcarrige return:\runicode ä:\u00e4"
VAR17='single quoted backslash:\\double quote:\"single quote:\'newline:\ntab:\tbackspace:\bformfeed:\fcarrige return:\runicode ä:\u00e4'
VAR18=no quote backslash:\\double quote:\"single quote:\'newline:\ntab:\tbackspace:\bformfeed:\fcarrige return:\runicode ä:\u00e4
VAR19= FOO 
VAR20=FOO\nBAR
VAR21="FOO" #"COMMENT"
VAR22=FOO \
BAR
VAR23="double\
quoted"
VAR24="double
quoted" BAZ
VAR25="double
quoted" #COMMENT
VAR26='single\'quoted'
VAR27='single''quoted'
VAR28='single-quoted' #COMMENT
VAR29='single-quoted'#COMMENT
VAR30='single-quoted' #COMMENT'
VAR31='single-quoted'#COMMENT'
VAR32='single
quoted'
VAR33=`back
ticks`
JSON1={"foo": "bar \n no quotes #"}
JSON2="{"foo": "bar \n double quotes #"}"
JSON3='{"foo": "bar \n single quotes #"}'
JSON4=`{"foo": "bar \n backticks #"}`
PRE_DEFINED=override
EOF="FOO

dotenv.js

{
  '11': '111111',
  VAR2: '',
  VAR3: 'EGG BACON" "AND SPAM',
  VAR5: 'FOO BAR',
  VAR6: 'FOO BAR',
  VAR8: 'FOO" ',
  BAR1: 'BAZ"',
  VAR9: 'FOO\nBAR2=BAZ',
  VAR10: '"FOO BAR" BAZ BLA',
  VAR12: '',
  VAR13: 'TEXT',
  VAR14: '#NO COMMNET',
  VAR15: '#NO COMMNET',
  VAR16: `double quoted backslash:\\\\double quote:\\"single quote:\\'newline:\n` +
    'tab:\\tbackspace:\\bformfeed:\\fcarrige return:\runicode ä:\\u00e4',
  VAR17: `single quoted backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR18: `no quote backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR19: 'FOO',
  VAR20: 'FOO\\nBAR',
  VAR21: 'FOO',
  VAR22: 'FOO \\',
  VAR23: 'double\\\nquoted',
  VAR24: '"double',
  VAR25: 'double\nquoted',
  VAR26: "single\\'quoted",
  VAR27: "single''quoted",
  VAR28: 'single-quoted',
  VAR29: 'single-quoted',
  VAR30: 'single-quoted',
  VAR31: 'single-quoted',
  VAR32: 'single\nquoted',
  VAR33: 'back\nticks',
  JSON1: '{"foo": "bar \\n no quotes',
  JSON2: '"{"foo": "bar \n double quotes',
  JSON3: '{"foo": "bar \\n single quotes #"}',
  JSON4: '{"foo": "bar \\n backticks #"}',
  PRE_DEFINED: 'not override',
  EOF: '"FOO'
}

nodejs.js

{
  VAR2: '',
  VAR3: '"EGG BACON" "AND SPAM"',
  '"VAR4"': 'BLUBB',
  '"VAR 4"': 'BLUBB',
  VAR5: '"FOO BAR"',
  VAR6: 'FOO BAR',
  VAR8: '"FOO" "',
  BAR1: 'BAZ"',
  BAR2: 'BAZ"',
  VAR10: '"FOO BAR" BAZ BLA',
  VAR12: '',
  VAR13: 'TEXT',
  VAR14: '#NO COMMNET',
  VAR15: '"',
  VAR16: `double quoted backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR17: `single quoted backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR18: `no quote backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR19: 'FOO',
  VAR20: 'FOO\\nBAR',
  VAR21: 'FOO" #"COMMENT',
  VAR22: 'FOO \\',
  VAR26: "single\\'quoted",
  VAR27: "single''quoted",
  VAR28: 'single-quoted',
  VAR29: 'single-quoted',
  VAR30: "single-quoted' #COMMENT",
  VAR31: "single-quoted'#COMMENT",
  JSON1: '{"foo": "bar \\n no quotes',
  JSON2: '{"foo": "bar \\n double quotes #"}',
  JSON3: '{"foo": "bar \\n single quotes #"}',
  JSON4: '{"foo": "bar \\n backticks #"}',
  PRE_DEFINED: 'not override'
}

python-dotenv-cli.js

{
  VAR2: '',
  VAR3: 'EGG BACON" "AND SPAM',
  '"VAR4"': 'BLUBB',
  '"VAR 4"': 'BLUBB',
  VAR5: '"FOO BAR" # COMMENT',
  VAR6: 'FOO BAR # COMMNET',
  VAR8: 'FOO" ',
  BAR1: 'BAZ"',
  VAR9: '"FOO',
  BAR2: 'BAZ"',
  VAR10: '"FOO BAR" BAZ BLA',
  VAR12: '#COMMENT',
  VAR13: 'TEXT#NO COMMENT',
  VAR14: '#NO COMMNET',
  VAR15: '#NO COMMNET',
  VAR16: `double quoted backslash:\\double quote:"single quote:'newline:\n` +
    'tab:\tbackspace:\bformfeed:\fcarrige return:\runicode ä:ä',
  VAR17: `single quoted backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR18: `no quote backslash:\\\\double quote:\\"single quote:\\'newline:\\ntab:\\tbackspace:\\bformfeed:\\fcarrige return:\\runicode ä:\\u00e4`,
  VAR19: 'FOO',
  VAR20: 'FOO\\nBAR',
  VAR21: 'FOO" #"COMMENT',
  VAR22: 'FOO \\',
  VAR23: '"double\\',
  VAR24: '"double',
  VAR25: '"double',
  VAR26: "single\\'quoted",
  VAR27: "single''quoted",
  VAR28: "'single-quoted' #COMMENT",
  VAR29: "'single-quoted'#COMMENT",
  VAR30: "single-quoted' #COMMENT",
  VAR31: "single-quoted'#COMMENT",
  VAR32: "'single",
  VAR33: '`back',
  JSON1: '{"foo": "bar \\n no quotes #"}',
  JSON2: '{"foo": "bar \n double quotes #"}',
  JSON3: '{"foo": "bar \\n single quotes #"}',
  JSON4: '`{"foo": "bar \\n backticks #"}`',
  PRE_DEFINED: 'override',
  EOF: '"FOO'
}