Intro

For duplication, we look at places in code where there are 6 or more lines of code that are exactly the same.
Before duplication is calculated, the code is cleaned to remove empty lines, comments, and frequently duplicated constructs such as imports.
You should aim at having as little as possible (<5%) of duplicated code as high-level of duplication can lead to maintenance difficulties, poor factoring, and logical contradictions.

Learn more...

Duplication Overall

9% duplication:

201,490 cleaned lines of cleaned code (without empty lines, comments, and frequently duplicated constructs such as imports)
19,540 duplicated lines

7,601 duplicates

Duplication per Extension

Duplication per Component (primary)

Longest Duplicates

The list of 50 longest duplicates.

See data for all 7,601 duplicates...

Size	#	Folders	Files	Lines	Code
430	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2780:3284 (11%) 3932:4436 (11%)	view
270	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	547:879 (7%) 1313:1645 (7%)	view
264	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1702:2018 (7%) 2426:2742 (7%)	view
263	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2024:2339 (7%) 2426:2741 (7%)	view
263	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1702:2017 (7%) 2024:2339 (7%)	view
64	x 2	src/harness src/harness	fourslashInterfaceImpl.ts fourslashInterfaceImpl.ts	1303:1366 (4%) 1515:1578 (4%)	view
60	x 2	src/testRunner/unittests/tscWatch src/testRunner/unittests/tscWatch	projectsWithReferences.ts projectsWithReferences.ts	202:272 (16%) 321:391 (16%)	view
49	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	619:690 (8%) 1093:1164 (5%)	view
47	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferences.ts projectReferences.ts	520:571 (3%) 712:763 (3%)	view
45	x 2	src/harness src/harness	fourslashInterfaceImpl.ts fourslashInterfaceImpl.ts	1432:1476 (3%) 1583:1627 (3%)	view
44	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	331:382 (2%) 1231:1282 (2%)	view
44	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	471:522 (2%) 1393:1444 (2%)	view
44	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	277:328 (2%) 1177:1228 (2%)	view
41	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	525:574 (2%) 1447:1496 (2%)	view
36	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	watchEnvironment.ts watchEnvironment.ts	327:363 (4%) 485:521 (4%)	view
36	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	943:985 (1%) 1682:1724 (1%)	view
35	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectsWithReferences.ts projectsWithReferences.ts	68:105 (7%) 308:345 (7%)	view
35	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	769:810 (1%) 1584:1625 (1%)	view
34	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	watchEnvironment.ts watchEnvironment.ts	369:405 (4%) 531:567 (4%)	view
33	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1498:1531 (<1%) 4231:4264 (<1%)	view
33	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	732:765 (<1%) 3079:3112 (<1%)	view
33	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1498:1531 (<1%) 3079:3112 (<1%)	view
33	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	732:765 (<1%) 4231:4264 (<1%)	view
32	x 2	src/testRunner/unittests src/testRunner/unittests	createMapShim.ts createSetShim.ts	4:36 (12%) 3:35 (13%)	view
31	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	4254:4284 (<1%) 4366:4396 (<1%)	view
31	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	3102:3132 (<1%) 3214:3244 (<1%)	view
31	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	3102:3132 (<1%) 4366:4396 (<1%)	view
31	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	3214:3244 (<1%) 4254:4284 (<1%)	view
30	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	3691:3720 (<1%) 3883:3912 (<1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	390:425 (1%) 1301:1336 (1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1868:1897 (<1%) 4227:4256 (<1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2592:2621 (<1%) 3075:3104 (<1%)	view
29	x 2	src/testRunner/unittests src/testRunner/unittests	reuseProgramStructure.ts reuseProgramStructure.ts	1024:1054 (2%) 1062:1092 (2%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	239:274 (1%) 1139:1174 (1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2190:2219 (<1%) 3075:3104 (<1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	1868:1897 (<1%) 3075:3104 (<1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2592:2621 (<1%) 4227:4256 (<1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	433:468 (1%) 1355:1390 (1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	196:231 (1%) 1085:1120 (1%)	view
29	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferencesSourcemap.ts projectReferencesSourcemap.ts	2190:2219 (<1%) 4227:4256 (<1%)	view
28	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	120:152 (1%) 998:1030 (1%)	view
28	x 2	src/testRunner/unittests src/testRunner/unittests	reuseProgramStructure.ts reuseProgramStructure.ts	543:570 (2%) 585:612 (2%)	view
28	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	156:188 (1%) 1034:1066 (1%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	1275:1305 (1%) 2015:2045 (1%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	rename.ts rename.ts	113:140 (11%) 147:174 (11%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	1059:1089 (1%) 1797:1827 (1%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	1167:1197 (1%) 1906:1936 (1%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	partialSemanticServer.ts syntacticServer.ts	166:193 (11%) 140:167 (17%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	projectReferenceCompileOnSave.ts projectReferenceCompileOnSave.ts	1221:1251 (1%) 1961:1991 (1%)	view
27	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	configuredProjects.ts configuredProjects.ts	293:320 (2%) 320:347 (2%)	view

Duplicated Units

The list of top 28 duplicated units.

See data for all 28 unit duplicates...

Size	#	Folders	Files	Lines	Code
16	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	675:691 1149:1165	view
15	x 2	src/compiler/transformers src/compiler/transformers	es2015.ts es2018.ts	2122:2137 491:506	view
15	x 2	src/testRunner/unittests/evaluation src/testRunner/unittests/evaluation	superInStaticInitializer.ts superInStaticInitializer.ts	103:118 126:141	view
11	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	getExportReferences.ts getExportReferences.ts	69:83 94:107	view
10	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	641:651 1115:1125	view
10	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	653:663 1127:1137	view
10	x 2	src/compiler/transformers src/compiler/transformers	generators.ts generators.ts	1368:1378 1409:1419	view
9	x 2	scripts/build src/harness	findUpDir.js findUpDir.ts	7:16 8:17	view
15	x 2	src/testRunner/unittests/evaluation src/testRunner/unittests/evaluation	superInStaticInitializer.ts superInStaticInitializer.ts	149:164 171:186	view
8	x 2	src/compiler/transformers src/compiler/transformers/module	classFields.ts module.ts	633:641 636:644	view
8	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	665:673 1139:1147	view
32	x 2	src/testRunner/unittests/tsbuild src/testRunner/unittests/tsbuildWatch	publicApi.ts publicApi.ts	84:117 80:113	view
7	x 2	src/compiler src/compiler	binder.ts binder.ts	1754:1761 1763:1770	view
7	x 2	src/compiler src/compiler	emitter.ts emitter.ts	1990:1997 3369:3376	view
7	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	693:700 1167:1174	view
7	x 2	src/compiler/transformers/module src/compiler/transformers/module	module.ts system.ts	1748:1757 1659:1666	view
7	x 2	src/harness src/harness	fakesHosts.ts harnessLanguageService.ts	154:161 157:164	view
7	x 2	src/harness src/harness	harnessIO.ts harnessIO.ts	1306:1313 1315:1322	view
7	x 3	src/testRunner/unittests src/testRunner/unittests/tsbuild src/testRunner/unittests/tsbuildWatch	customTransforms.ts publicApi.ts publicApi.ts	46:53 87:94 83:90	view
7	x 3	src/testRunner/unittests src/testRunner/unittests/tsbuild src/testRunner/unittests/tsbuildWatch	customTransforms.ts publicApi.ts publicApi.ts	62:69 103:110 99:106	view
7	x 2	src/testRunner/unittests/evaluation src/testRunner/unittests/evaluation	forAwaitOf.ts forAwaitOf.ts	7:14 33:40	view
7	x 2	src/testRunner/unittests/services/extract src/testRunner/unittests/services/extract	functions.ts functions.ts	9:16 67:74	view
6	x 2	src/compiler src/compiler	emitter.ts emitter.ts	3408:3414 3498:3504	view
6	x 2	src/compiler src/compiler	parser.ts parser.ts	7751:7757 8004:8010	view
6	x 2	src/compiler/transformers src/compiler/transformers	classFields.ts generators.ts	1641:1647 1951:1957	view
6	x 2	src/compiler/transformers src/compiler/transformers	declarations.ts declarations.ts	182:188 197:203	view
6	x 2	src/compiler/transformers src/compiler/transformers	es2017.ts es2018.ts	632:639 1107:1113	view
6	x 2	src/testRunner/unittests/tsserver src/testRunner/unittests/tsserver	declarationFileMaps.ts declarationFileMaps.ts	205:211 221:227	view