Mixed Messages: Measuring Conformance and Non-Interference in TypeScript

Jack Williams; J. Garrett  Morris; Philip Wadler; Jakub Zalewski

doi:10.4230/LIPIcs.ECOOP.2017.28

Mixed Messages: Measuring Conformance and Non-Interference in TypeScript

Jack Williams, J. Garrett Morris, Philip Wadler, Jakub Zalewski

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract / Description of output

TypeScript participates in the recent trend among programming languages to support gradual typing. The DefinitelyTyped Repository for TypeScript supplies type definitions for over 2000 popular JavaScript libraries. However, there is no guarantee that implementations conform to their corresponding declarations.
We present a practical evaluation of gradual typing for TypeScript. We have developed a tool for use with TypeScript, based on the polymorphic blame calculus, for monitoring JavaScript libraries and TypeScript clients against the TypeScript definition. We apply our tool, TypeScript TPD, to those libraries in the DefinitelyTyped Repository which had adequate test code to use. Of the 122 libraries we checked, 62 had cases where either the library or its tests failed to conform to the declaration.
Gradual typing should satisfy non-interference. Monitoring a program should never change its behaviour, except to raise a type error should a value not conform to its declared type. However, our experience also suggests serious technical concerns with the use of the JavaScript proxy mechanism for enforcing contracts. Of the 122 libraries we checked, 22 had cases where the library or its tests violated non-interference.

Original language	English
Title of host publication	The European Conference on Object-Oriented Programming (ECOOP 2017)
Publisher	Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany
Pages	1-28
Number of pages	28
ISBN (Print)	978-3-95977-035-4
DOIs	https://doi.org/10.4230/LIPIcs.ECOOP.2017.28
Publication status	Published - 23 Jun 2017
Event	31st European Conference on Object-Oriented Programming - Barcelona, Spain Duration: 18 Jun 2017 → 23 Jun 2017 https://2017.ecoop.org/track/ecoop-2017-papers

Publication series

Name	Leibniz International Proceedings in Informatics (LIPIcs)
Publisher	Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik
Volume	74
ISSN (Print)	1868-8969

Conference

Conference	31st European Conference on Object-Oriented Programming
Abbreviated title	ECOOP 2017
Country/Territory	Spain
City	Barcelona
Period	18/06/17 → 23/06/17
Internet address	https://2017.ecoop.org/track/ecoop-2017-papers

Access to Document

10.4230/LIPIcs.ECOOP.2017.28

ecoop17-mixed-messages-2Accepted author manuscript, 503 KB
LIPIcs-ECOOP-2017-28Final published version, 521 KBLicence: Creative Commons: Attribution (CC-BY)

http://drops.dagstuhl.de/opus/volltexte/2017/7264/Licence: Creative Commons: Attribution (CC-BY)

From Data Types to Session Types - A Basis for Concurrency and Distribution
Wadler, P.
EPSRC
20/05/13 → 19/11/20
Project: Research

Cite this

Williams, J., Morris, J. G., Wadler, P., & Zalewski, J. (2017). Mixed Messages: Measuring Conformance and Non-Interference in TypeScript. In The European Conference on Object-Oriented Programming (ECOOP 2017) (pp. 1-28). Article 39 (Leibniz International Proceedings in Informatics (LIPIcs); Vol. 74). Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany. https://doi.org/10.4230/LIPIcs.ECOOP.2017.28

@inproceedings{bc7b3d2a3745463085b110108aed415a,

title = "Mixed Messages: Measuring Conformance and Non-Interference in TypeScript",

abstract = "TypeScript participates in the recent trend among programming languages to support gradual typing. The DefinitelyTyped Repository for TypeScript supplies type definitions for over 2000 popular JavaScript libraries. However, there is no guarantee that implementations conform to their corresponding declarations.We present a practical evaluation of gradual typing for TypeScript. We have developed a tool for use with TypeScript, based on the polymorphic blame calculus, for monitoring JavaScript libraries and TypeScript clients against the TypeScript definition. We apply our tool, TypeScript TPD, to those libraries in the DefinitelyTyped Repository which had adequate test code to use. Of the 122 libraries we checked, 62 had cases where either the library or its tests failed to conform to the declaration. Gradual typing should satisfy non-interference. Monitoring a program should never change its behaviour, except to raise a type error should a value not conform to its declared type. However, our experience also suggests serious technical concerns with the use of the JavaScript proxy mechanism for enforcing contracts. Of the 122 libraries we checked, 22 had cases where the library or its tests violated non-interference.",

author = "Jack Williams and Morris, {J. Garrett} and Philip Wadler and Jakub Zalewski",

year = "2017",

month = jun,

day = "23",

doi = "10.4230/LIPIcs.ECOOP.2017.28",

language = "English",

isbn = "978-3-95977-035-4",

series = "Leibniz International Proceedings in Informatics (LIPIcs)",

publisher = "Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany",

pages = "1--28",

booktitle = "The European Conference on Object-Oriented Programming (ECOOP 2017)",

note = "31st European Conference on Object-Oriented Programming, ECOOP 2017 ; Conference date: 18-06-2017 Through 23-06-2017",

url = "https://2017.ecoop.org/track/ecoop-2017-papers",

}

Williams, J, Morris, JG, Wadler, P & Zalewski, J 2017, Mixed Messages: Measuring Conformance and Non-Interference in TypeScript. in The European Conference on Object-Oriented Programming (ECOOP 2017)., 39, Leibniz International Proceedings in Informatics (LIPIcs), vol. 74, Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, pp. 1-28, 31st European Conference on Object-Oriented Programming, Barcelona, Spain, 18/06/17. https://doi.org/10.4230/LIPIcs.ECOOP.2017.28

Mixed Messages: Measuring Conformance and Non-Interference in TypeScript. / Williams, Jack; Morris, J. Garrett ; Wadler, Philip et al.
The European Conference on Object-Oriented Programming (ECOOP 2017). Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, 2017. p. 1-28 39 (Leibniz International Proceedings in Informatics (LIPIcs); Vol. 74).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - Mixed Messages: Measuring Conformance and Non-Interference in TypeScript

AU - Williams, Jack

AU - Morris, J. Garrett

AU - Wadler, Philip

AU - Zalewski, Jakub

PY - 2017/6/23

Y1 - 2017/6/23

N2 - TypeScript participates in the recent trend among programming languages to support gradual typing. The DefinitelyTyped Repository for TypeScript supplies type definitions for over 2000 popular JavaScript libraries. However, there is no guarantee that implementations conform to their corresponding declarations.We present a practical evaluation of gradual typing for TypeScript. We have developed a tool for use with TypeScript, based on the polymorphic blame calculus, for monitoring JavaScript libraries and TypeScript clients against the TypeScript definition. We apply our tool, TypeScript TPD, to those libraries in the DefinitelyTyped Repository which had adequate test code to use. Of the 122 libraries we checked, 62 had cases where either the library or its tests failed to conform to the declaration. Gradual typing should satisfy non-interference. Monitoring a program should never change its behaviour, except to raise a type error should a value not conform to its declared type. However, our experience also suggests serious technical concerns with the use of the JavaScript proxy mechanism for enforcing contracts. Of the 122 libraries we checked, 22 had cases where the library or its tests violated non-interference.

AB - TypeScript participates in the recent trend among programming languages to support gradual typing. The DefinitelyTyped Repository for TypeScript supplies type definitions for over 2000 popular JavaScript libraries. However, there is no guarantee that implementations conform to their corresponding declarations.We present a practical evaluation of gradual typing for TypeScript. We have developed a tool for use with TypeScript, based on the polymorphic blame calculus, for monitoring JavaScript libraries and TypeScript clients against the TypeScript definition. We apply our tool, TypeScript TPD, to those libraries in the DefinitelyTyped Repository which had adequate test code to use. Of the 122 libraries we checked, 62 had cases where either the library or its tests failed to conform to the declaration. Gradual typing should satisfy non-interference. Monitoring a program should never change its behaviour, except to raise a type error should a value not conform to its declared type. However, our experience also suggests serious technical concerns with the use of the JavaScript proxy mechanism for enforcing contracts. Of the 122 libraries we checked, 22 had cases where the library or its tests violated non-interference.

U2 - 10.4230/LIPIcs.ECOOP.2017.28

DO - 10.4230/LIPIcs.ECOOP.2017.28

M3 - Conference contribution

SN - 978-3-95977-035-4

T3 - Leibniz International Proceedings in Informatics (LIPIcs)

SP - 1

EP - 28

BT - The European Conference on Object-Oriented Programming (ECOOP 2017)

PB - Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany

T2 - 31st European Conference on Object-Oriented Programming

Y2 - 18 June 2017 through 23 June 2017

ER -

Mixed Messages: Measuring Conformance and Non-Interference in TypeScript

Abstract / Description of output

Publication series

Conference

Access to Document

Fingerprint

Projects

From Data Types to Session Types - A Basis for Concurrency and Distribution

Cite this