A command-line Dart script and library that generates JSON or CSV data in bulk. If you are building an IT system, then the chances are you'll need to populate a database (whether SQL or NoSQL) with some reasonably realistic data to test and benchmark with.
This is a port of the Node.js datamaker tool, see the AUTHORS file for further details.
The dartamaker tool allows sample data to be created by supplying:
- a template of how the data is to look. The data can contain multiple placeholders where sample data will be inserted e.g.
{{firstname}},{{lastname}},{{date}}
. - the format of the output data:
none
,json
xml
orcsv
. This effects how the generated string data is processed prior to delivery. - the number of records to be created.
Quick example:
$ dartamaker --format csv --iterations 5 "{{uuid}},{{date}},{{firstname}} {{surname}},{{email}}"
10U9SHHE2463IH9E,1970-10-12,Marylee Dodge,meagan-harwell@betaine.com
379QYC80U5KYQP4D,1994-11-09,Melany Fuqua,jennette.labonte@yahoo.com
DERC4Y2BQ6HCI0HI,1983-08-11,Cathleen Leal,earlenemattson@gmail.com
00K8FEGZJO31Q08O,2005-06-18,Louie Lee,tonisha.short@hotmail.com
JDYSVPTAEXKEF9D8,1982-10-29,Dionne Vann,martin.renfro@hemicrane.com
You can activate dartamaker for command line use by executing the following command :-
pub global activate dartamaker
--template
/-t
- the path of the template file e.g--template /path/to/template.txt
--format
/-f
- the target file format (none
,csv
,json
orxml
). Defaultnone
e.g.--format json
--iterations
/-i
- the number of records to create. Default1
e.g.--iterations 5000
--list
/-l
- list the available tags
The command line parameters must come before any input to process.
The template for a CSV file can be stored in a text file and supplied with the --template/-t
parameter. Create a text file containing the following template:
{{uuid}},{{date}},{{time}},{{firstname}} {{surname}},{{street}},{{town}},{{zip}} {{statecode}},{{longitude}},{{latitude}}
The template contains the layout of each line of data, with placeholders for where the dynamic data is inserted. Save it as template.txt
.
You may now run dartamaker
using this template:
$ dartamaker -t ./template.txt -f csv -i 500
JSON data is generated in a similar way. This time our template represents a single JSON document:
{
"_id": "{{uuid}}",
"name": "{{firstname}} {{surname}}",
"dob": "{{date 2014-01-01}}",
"address": {
"street": "{{street}}",
"town": "{{town}}",
"postode": "{{postcode}}"
},
"telephone": "{{tel}}",
"pets": ["{{cat}}","{{dog}}"],
"score": {{float 1,10,1}},
"email": "{{email}}",
"url": "{{website}}",
"description": "{{words 20}}",
"verified": {{boolean 0.75}},
"salary": {{float 10000,70000,0}}
}
Save the template as template.json
.
Run the dartamaker
as before but with json
as the format parameter:
$ dartamaker -t ./template.json -f json -i 500
{"_id":"G3BX8LUGFHAGFX7A","name":"Chelsea Ballou","dob":"2003-10-10","address":{"street":"0055 Houghton","town":"Tynemouth","postode":"HU0 4GF"},"telephone":"+509-9934-828-292","pets":["Murphy","Nala"],"score":9.5,"email":"nelson_jones@spousy.com","url":"http://propriospinal.com","description":"outmate solarometer Zapara tyro keratinize galactolytic divestiture swardy petaled tearlessness adjutorious epigynum jotation tavernly suggestum Eriophyes straint Tsuma malignation autoscience","verified":true,"salary":32082}
...
Create an XML template e.g. template.xml
:
<?xml version="1.0"?>
<company>
<name>{{company}}</name>
<address>
<street>{{street}}</street>
<city>{{city}}</city>
<state>{{state}}</state>
<zip>{{statecode}}{{zip}}</zip>
</address>
<ceo>{{firstname}} {{surname}}</ceo>
<dateCreated>{{date}}</dateCreated>
</company>
Run the dartamaker as before but with xml
as the format parameter:
$ dartamaker -t ./template.xml -f xml -i 500
<?xml version="1.0"?><company> <name>Consulting </name> <address> <street>5270 Bispham Lane</street> <city>Saint Louis</city> <state>Alabama</state> <zip>AZ83647</zip> </address> <ceo>Jefferey Harvey</ceo> <dateCreated>2009-10-28</dateCreated></company>
...
The Mustache-style tags you may use are listed below. Some tags allow extra parameters to be supplied to affect the range of random data generated
The code for the tags can be found in the plugins
folder of the source code.
- A-E - airport autoinc boolean cat city company country creditcard currency date date_iso digits dog domainname email emojii
- F-O - firstname float integer last latitude letters longitude oneof name normal
- P-T - postcode price state statecode street surname tel time timestamp title tld town
- U-Z - url uuid website word words zip
Three-digit airport code.
Parameters: none
e.g.
{{airport}} ---> MTK
Auto-incrementing number.
Parameters: none
e.g.
{{autoinc}} ---> 1
{{autoinc}} ---> 2
Boolean value.
Parameters:
- probability of being true (default 0.5)
e.g.
{{boolean}} ---> false
{{boolean 0.95}} ---> true
Cat name.
Parameters: none
e.g.
{{cat}} ---> Smokey
US city name.
Parameters: none
e.g.
{{city}} ---> Fremont
Company name.
Parameters: none
e.g.
{{company}} ---> Venusian Software Corp
Country name.
Parameters: none
e.g.
{{country}} ---> Lebanon
UK county name.
Parameters: none
e.g.
{{county}} ---> Derbyshire
Credit card number.
Parameters: none
e.g.
{{creditcard}} ---> 6011867289904845
Currency code.
Parameters: none
e.g.
{{currency}} ---> USD
Random date in YYYY-MM-DD format.
Parameters:
- min - minimum date (default '1970-01-01')
- max - maximum date (default 'now')
e.g.
{{date}} ---> 1977-02-28
{{date 2015-01-01}} ---> 2018-08-02 // date after 2015-01-01
{{date 2015-01-01 2016-01-01}} ---> 2015-04-23 // date in 2015
Random date in ISO-8601 format.
Parameters:
- min - minimum date (default '1970-01-01')
- max - maximum date (default 'now')
e.g.
{{date_iso}} ---> 2013-05-24T02:44:04.687Z
{{date_iso 2015-01-01}} ---> 2018-07-09T22:15:30.512Z // date after 2015-01-01
{{date_iso 2015-01-01 2016-01-01}} ---> 2015-04-21T18:08:33.979Z // date in 2015
String of numerals.
Parameters:
- numDigits (default 5)
e.g.
{{digits}} ---> 06984
{{digits 8}} ---> 61103920
Dog name.
Parameters: none
e.g.
{{dog}} ---> Lucky
Domain name.
Parameters: none
e.g.
{{domainname}} ---> yallaer.com
Email address.
Parameters: none
e.g.
{{email}} ---> jermaine.buchanan@drilling.com
Emojii.
Parameters:
- numChars - number of characters (default 1)
e.g.
{{emojii}} ---> π¦
{{emojii 3}} ---> πΉβπΊ
Human first name.
Parameters:
e.g.
{{firstname}} ---> Bethan
Floating point number.
Parameters:
- min (default 1)
- max (default 100)
- decimalPlaces (default 4)
e.g.
{{float}} ---> 13.8592
{{float 1000,2000,2}} ---> 1750.06
Integer number.
Parameters:
- min (default 1)
- max (default 100)
e.g.
{{integer}} ---> 99
{{integer 1000,2000}} ---> 1523
The last generate value of the supplied tag. This is used to re-use generated data elsewhere in your template.
Parameters:
- tag - the name of the tag
e.g.
{{last uuid}} ---> HSFC5LQPCP84IVY7 (the last uuid that was generated by dartamaker)
Decimal latitude.
Parameters: none
e.g.
{{latitude}} ---> -54.4371
String of uppercase characters.
Parameters:
- numLetters (default 5)
e.g.
{{letters}} ---> TVEHJ
{{letters 10}} ---> WOBOJRJFCU
Decimal longitude.
Parameters: none
e.g.
{{longitude}} ---> 175.2526
Picks one of supplied values.
Parameters: any number of strings
e.g.
{{oneof Gryffindor Hufflepuff Ravenclaw Slytherin}} ---> Slytherin
Combination for firstname and surname. Equivalent of {{firstname}} {{surname}}
.
Parameters: none
e.g.
{{name}} ---> Anna Flint
Generates numbers on a normal distribution
Parameters:
- mean - centre of distribution (default 50)
- stddev - standard deviation (default 1)
- decimalPlaces - number of decimal places (default 4)
e.g.
{{normal}} ---> 50.1097
{{normal 20000,1000,2}} ---> 20370.88
UK postcode.
Parameters: none
e.g.
{{postcode}} ---> KT4 0XS
Floating point price.
Parameters:
- min (default 1)
- max (default 100)
e.g.
{{price}} ---> 65.29
{{price 500 700}} ---> 521.98
US state name.
Parameters: none
e.g.
{{state}} ---> Ohio
2-letter US state code.
Parameters: none
e.g.
{{statecode}} ---> NC
Street address.
Parameters: none
e.g.
{{street}} ---> 6502 Chantler Avenue
Human surname.
Parameters: none
e.g.
{{surname}} ---> Doyle-Tyson
International telephone number.
Parameters: none
e.g.
{{tel}} ---> +43-3040-100-474
Time in HH:MM:SS format.
Parameters: none
e.g.
{{time}} ---> 10:45:59
Timestamp in milliseconds since 1970.
Parameters:
- min - minimum timestamp (default 0)
- max - maximum timestamp (default 'now')
e.g.
{{timestamp}} ---> 351543517819
{{timestamp 946684800000}} --> 1163308913102 // timestamp after 2000-01-01
{{timestamp 946684800000,978307200000}} --> 959753617250 // timestamp in year 2000
Honorific or title e.g. Mr, Mrs etc.
Parameters: none
e.g.
{{title}} ---> Reverend
Top level domain, or common domain name ending.
Parameters: none
e.g.
{{tld}} ---> gov.pr
UK town name.
Parameters: none
e.g.
{{town}} ---> Dudley
Full URL.
Parameters: none
e.g.
{{url}} ---> https://www.jovinianist.com/microcosmology.html?adrenalone=VEF0TSB23N04V8MO
Unique identifier.
Parameters: none
e.g.
{{uuid}} ---> C3QTU8YIVKZY126Q
Full website URL.
Parameters: none
e.g.
{{website}} ---> http://unlyrically.com
Single word.
Parameters: none
e.g.
{{word}} ---> synentognathous
Multiple words.
Parameters:
- count (default 5)
e.g.
{{words}} ---> piacularly burp archisymbolical glumaceous Calinago
{{words 2}} --->Xenomorpha mauler
US ZIP code.
Parameters: none
e.g.
{{zip}} ---> 69882
The --format
/-f
parameter defines
- how the text in each substitution is pre-processed before output e.g. in
json
mode double quotes are escaped correctly. - how each line of output is processed prior to output e.g. in
json
mode the completed template is parsed to check it is valid JSON before being output on a a single line followed by a\n
character
The code for the formatters can be found in the formatters
folder of the source code.
The data generated by this tool is biased towards UK and US data sets. The names, towns, streets and postcodes are gleaned from western data sets. If you need data that resembles a different geography or contains more challenging character sets, then the feel free to fork the code and modify the stock data from the plugins
folder.
Note that generating an address with {{street}},{{city}},{{state}},{{statecode}}{{zip}}
will generate that appears at a glance to be a reasonble address, but is patently nonsense:
$ dartamaker "{{street}},{{city}},{{state}},{{statecode}}{{zip}}"
6682 Crowcroft Circle,Nashua,New York,UT00769
The plugins do not coordinate with each other to ensure that the street exists in the city, or that the city exists in the state, or that the state code matches the state. That would require a more sophisticated and much larger data set!
Also note that the email addresses, zip codes, domain names, telephone numbers, websites and postcodes are fabricated. Airports, towns, states, state codes, cities, counties, countries and currencies are real.