data source name parser

Overview

• query params
• validations
• assertions

Validation

parseDsn wraps its result in a discriminated union to enable the retrieval of validation errors. No try... catchneeded and full typescript support.

Reason codes are guaranteed in semantic versions and messages does not leak credentials

const parsed = parseDsn("redis://localhost:65636");
assert.deepEqual(parsed, {
  success: false,
  reason: "INVALID_PORT",
  message: "Invalid port: 65636",
});
if (!parsed.success) {
  // `success: false` narrows the type to
  // {
  //   reason: 'PARSE_ERROR'|'INVALID_ARGUMENT'|...
  //   message: string
  // }
  log(parsed.reason);
}

Reason	Message	Comment
'PARSE_ERROR'	Cannot parse DSN	Regexp failed
'INVALID_ARGUMENT'	DSN must be a string
'EMPTY_DSN'	DSN cannot be empty
'INVALID_PORT'	Invalid port: ${port}	[1-65535]

Usage

import { parseDsn } from 'dsnp';

const dsn = 'redis://user:p@/ss@localhost:6379/0?ssl=true''

const parsed = parseDsn(dsn);

if (parsed.success) {
  assert.deepEqual(parsed.value, {
    driver: 'redis',
    pass: 'p@/ss',
    host: 'localhost',
    user: 'user',
    port: 6379,
    db: '0',
    params: {
      ssl: true,
    },
  });
} else {
  assert.deepEqual(parsed, {
    success: false,
    // Reasons might vary
    reason: 'INVALID_PORT',
    message: 'Invalid http port: 12345678',
  });
}

Params	Type	Description
lowercaseDriver	<boolean>	Driver name in lowercase, default false
overrides	DSN must be a string

Packaging

Generates a platform-dependant script used to register the custom URI handler 'dsn3:', which can be used to execute DSN3 from other applications.

#!/usr/bin/env python3
'''
Generates a platform-dependant script used to register the custom URI handler 'dsn3:',
which can be used to execute DSN3 from other applications.

How to use:
- once the 'dsn3:' URI handler is registered, other applications can invoke DSN3
- standard parameters MUST be URL-encoded and provided after the URI
'''

import os
import platform
import sys

n = platform.system()
text = None
outname = None

if n == 'Windows':
  template = r'''Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Classes\dsn3]
"URL Protocol"=""
@="URL:dsn3 protocol"

[HKEY_CURRENT_USER\Software\Classes\dsn3\DefaultIcon]
@="dsn3.exe,1"

[HKEY_CURRENT_USER\Software\Classes\dsn3\shell]

[HKEY_CURRENT_USER\Software\Classes\dsn3\shell\open]

[HKEY_CURRENT_USER\Software\Classes\dsn3\shell\open\command]
@="\"%s\" \"%%1\""
'''
  path = os.path.abspath(os.getcwd() + r'\..\..\dsn3_wincon.bat')
  text = template % path.replace('\\', '\\\\')
  outname = 'RegisterDsn3UriScheme.reg'

elif n == 'Linux':
  template = r'''#!/bin/sh
set -uex

if which xdg-mime > /dev/null; then
  DESKTOP_DIR="$HOME/.local/share/applications"
  DESKTOP_PATH="$DESKTOP_DIR/dsn3-opener.desktop"

  cat << EOF > "$DESKTOP_PATH"
[Desktop Entry]
Type=Application
Name=DSN3 scheme handler
Exec="{dsn3_bin_path}" %u
StartupNotify=true
MimeType=x-scheme-handler/dsn3;
EOF

  xdg-mime default "$DESKTOP_PATH" x-scheme-handler/dsn3
  update-desktop-database "$DESKTOP_DIR"
fi

if which gconftool-2 > /dev/null; then
  gconftool-2 -t string -s /desktop/gnome/url-handlers/dsn3/command '"{dsn3_bin_path}" "%s"'
  gconftool-2 -s /desktop/gnome/url-handlers/dsn3/needs_terminal false -t bool
  gconftool-2 -s /desktop/gnome/url-handlers/dsn3/enabled true -t bool
fi
'''
  path = os.path.abspath(os.getcwd() + r'/../../dsn3_linux.sh')
  text = template.format(dsn3_bin_path=path)
  outname = 'RegisterDsn3UriScheme.sh'

else:
  print('Not implemented for platform %s!' % n)
  sys.exit(-1)

with open(outname, 'w') as f:
  f.write(text)
print('Execute the generated file %s to register the DSN3 URI scheme.' % outname)