ESLintESLint Formatters
ESLint comes with several built-in formatters to control the appearance of the linting results, and supports third-party formatters as well.
The built-in formatter options are:
Example Source
Examples of each formatter were created from linting fullOfProblems.js using the .eslintrc configuration shown below.
fullOfProblems.js
function addOne(i) {
if (i != NaN) {
return i ++
} else {
return
}
};
.eslintrc:
{
"extends": "eslint:recommended",
"rules": {
"consistent-return": 2,
"indent" : [1, 4],
"no-else-return" : 1,
"semi" : [1, "always"],
"space-unary-ops" : 2
}
}
Output Examples
checkstyle
<?xml version="1.0" encoding="utf-8"?><checkstyle version="4.3"><file name="fullOfProblems.js"><error line="1" column="10" severity="error" message="'addOne' is defined but never used (no-unused-vars)" source="eslint.rules.no-unused-vars" /><error line="2" column="9" severity="error" message="Use the isNaN function to compare with NaN. (use-isnan)" source="eslint.rules.use-isnan" /><error line="3" column="16" severity="error" message="Unexpected space before unary operator '++'. (space-unary-ops)" source="eslint.rules.space-unary-ops" /><error line="3" column="20" severity="warning" message="Missing semicolon. (semi)" source="eslint.rules.semi" /><error line="4" column="12" severity="warning" message="Unexpected 'else' after 'return'. (no-else-return)" source="eslint.rules.no-else-return" /><error line="5" column="7" severity="warning" message="Expected indentation of 8 space characters but found 6. (indent)" source="eslint.rules.indent" /><error line="5" column="7" severity="error" message="Expected a return value. (consistent-return)" source="eslint.rules.consistent-return" /><error line="5" column="13" severity="warning" message="Missing semicolon. (semi)" source="eslint.rules.semi" /><error line="7" column="2" severity="error" message="Unnecessary semicolon. (no-extra-semi)" source="eslint.rules.no-extra-semi" /></file></checkstyle>
compact
fullOfProblems.js: line 1, col 10, Error - 'addOne' is defined but never used (no-unused-vars)
fullOfProblems.js: line 2, col 9, Error - Use the isNaN function to compare with NaN. (use-isnan)
fullOfProblems.js: line 3, col 16, Error - Unexpected space before unary operator '++'. (space-unary-ops)
fullOfProblems.js: line 3, col 20, Warning - Missing semicolon. (semi)
fullOfProblems.js: line 4, col 12, Warning - Unexpected 'else' after 'return'. (no-else-return)
fullOfProblems.js: line 5, col 7, Warning - Expected indentation of 8 space characters but found 6. (indent)
fullOfProblems.js: line 5, col 7, Error - Expected a return value. (consistent-return)
fullOfProblems.js: line 5, col 13, Warning - Missing semicolon. (semi)
fullOfProblems.js: line 7, col 2, Error - Unnecessary semicolon. (no-extra-semi)
9 problems
html
jslint-xml
<?xml version="1.0" encoding="utf-8"?><jslint><file name="fullOfProblems.js"><issue line="1" char="10" evidence="function addOne(i) {" reason="'addOne' is defined but never used (no-unused-vars)" /><issue line="2" char="9" evidence=" if (i != NaN) {" reason="Use the isNaN function to compare with NaN. (use-isnan)" /><issue line="3" char="16" evidence=" return i ++" reason="Unexpected space before unary operator '++'. (space-unary-ops)" /><issue line="3" char="20" evidence=" return i ++" reason="Missing semicolon. (semi)" /><issue line="4" char="12" evidence=" } else {" reason="Unexpected 'else' after 'return'. (no-else-return)" /><issue line="5" char="7" evidence=" return" reason="Expected indentation of 8 space characters but found 6. (indent)" /><issue line="5" char="7" evidence=" return" reason="Expected a return value. (consistent-return)" /><issue line="5" char="13" evidence=" return" reason="Missing semicolon. (semi)" /><issue line="7" char="2" evidence="};" reason="Unnecessary semicolon. (no-extra-semi)" /></file></jslint>
json
[{"filePath":"fullOfProblems.js","messages":[{"ruleId":"no-unused-vars","severity":2,"message":"'addOne' is defined but never used","line":1,"column":10,"nodeType":"Identifier","source":"function addOne(i) {"},{"ruleId":"use-isnan","severity":2,"message":"Use the isNaN function to compare with NaN.","line":2,"column":9,"nodeType":"BinaryExpression","source":" if (i != NaN) {"},{"ruleId":"space-unary-ops","severity":2,"message":"Unexpected space before unary operator '++'.","line":3,"column":16,"nodeType":"UpdateExpression","source":" return i ++","fix":{"range":[57,58],"text":""}},{"ruleId":"semi","severity":1,"message":"Missing semicolon.","line":3,"column":20,"nodeType":"ReturnStatement","source":" return i ++","fix":{"range":[60,60],"text":";"}},{"ruleId":"no-else-return","severity":1,"message":"Unexpected 'else' after 'return'.","line":4,"column":12,"nodeType":"BlockStatement","source":" } else {"},{"ruleId":"indent","severity":1,"message":"Expected indentation of 8 space characters but found 6.","line":5,"column":7,"nodeType":"ReturnStatement","source":" return","fix":{"range":[80,80],"text":" "}},{"ruleId":"consistent-return","severity":2,"message":"Expected a return value.","line":5,"column":7,"nodeType":"ReturnStatement","source":" return"},{"ruleId":"semi","severity":1,"message":"Missing semicolon.","line":5,"column":13,"nodeType":"ReturnStatement","source":" return","fix":{"range":[86,86],"text":";"}},{"ruleId":"no-extra-semi","severity":2,"message":"Unnecessary semicolon.","line":7,"column":2,"nodeType":"EmptyStatement","source":"};","fix":{"range":[94,95],"text":""}}],"errorCount":5,"warningCount":4}]
junit
<?xml version="1.0" encoding="utf-8"?>
<testsuites>
<testsuite package="org.eslint" time="0" tests="9" errors="9" name="fullOfProblems.js">
<testcase time="0" name="org.eslint.no-unused-vars"><failure message="'addOne' is defined but never used"><![CDATA[line 1, col 10, Error - 'addOne' is defined but never used (no-unused-vars)]]></failure></testcase>
<testcase time="0" name="org.eslint.use-isnan"><failure message="Use the isNaN function to compare with NaN."><![CDATA[line 2, col 9, Error - Use the isNaN function to compare with NaN. (use-isnan)]]></failure></testcase>
<testcase time="0" name="org.eslint.space-unary-ops"><failure message="Unexpected space before unary operator '++'."><![CDATA[line 3, col 16, Error - Unexpected space before unary operator '++'. (space-unary-ops)]]></failure></testcase>
<testcase time="0" name="org.eslint.semi"><failure message="Missing semicolon."><![CDATA[line 3, col 20, Warning - Missing semicolon. (semi)]]></failure></testcase>
<testcase time="0" name="org.eslint.no-else-return"><failure message="Unexpected 'else' after 'return'."><![CDATA[line 4, col 12, Warning - Unexpected 'else' after 'return'. (no-else-return)]]></failure></testcase>
<testcase time="0" name="org.eslint.indent"><failure message="Expected indentation of 8 space characters but found 6."><![CDATA[line 5, col 7, Warning - Expected indentation of 8 space characters but found 6. (indent)]]></failure></testcase>
<testcase time="0" name="org.eslint.consistent-return"><failure message="Expected a return value."><![CDATA[line 5, col 7, Error - Expected a return value. (consistent-return)]]></failure></testcase>
<testcase time="0" name="org.eslint.semi"><failure message="Missing semicolon."><![CDATA[line 5, col 13, Warning - Missing semicolon. (semi)]]></failure></testcase>
<testcase time="0" name="org.eslint.no-extra-semi"><failure message="Unnecessary semicolon."><![CDATA[line 7, col 2, Error - Unnecessary semicolon. (no-extra-semi)]]></failure></testcase>
</testsuite>
</testsuites>
stylish
fullOfProblems.js
1:10 error 'addOne' is defined but never used no-unused-vars
2:9 error Use the isNaN function to compare with NaN use-isnan
3:16 error Unexpected space before unary operator '++' space-unary-ops
3:20 warning Missing semicolon semi
4:12 warning Unexpected 'else' after 'return' no-else-return
5:7 warning Expected indentation of 8 space characters but found 6 indent
5:7 error Expected a return value consistent-return
5:13 warning Missing semicolon semi
7:2 error Unnecessary semicolon no-extra-semi
✖ 9 problems (5 errors, 4 warnings)
table
fullOfProblems.js
║ Line │ Column │ Type │ Message │ Rule ID ║
╟──────────┼──────────┼──────────┼────────────────────────────────────────────────────────┼──────────────────────╢
║ 1 │ 10 │ error │ 'addOne' is defined but never used │ no-unused-vars ║
║ 2 │ 9 │ error │ Use the isNaN function to compare with NaN. │ use-isnan ║
║ 3 │ 16 │ error │ Unexpected space before unary operator '++'. │ space-unary-ops ║
║ 3 │ 20 │ warning │ Missing semicolon. │ semi ║
║ 4 │ 12 │ warning │ Unexpected 'else' after 'return'. │ no-else-return ║
║ 5 │ 7 │ warning │ Expected indentation of 8 space characters but │ indent ║
║ │ │ │ found 6. │ ║
║ 5 │ 7 │ error │ Expected a return value. │ consistent-return ║
║ 5 │ 13 │ warning │ Missing semicolon. │ semi ║
║ 7 │ 2 │ error │ Unnecessary semicolon. │ no-extra-semi ║
╔════════════════════════════════════════════════════════════════════════════════════════════════════════════════╗
║ 5 Errors ║
╟────────────────────────────────────────────────────────────────────────────────────────────────────────────────╢
║ 4 Warnings ║
╚════════════════════════════════════════════════════════════════════════════════════════════════════════════════╝
tap
TAP version 13
1..1
not ok 1 - fullOfProblems.js
---
message: "'addOne' is defined but never used"
severity: error
data:
line: 1
column: 10
ruleId: no-unused-vars
messages:
- message: Use the isNaN function to compare with NaN.
severity: error
data:
line: 2
column: 9
ruleId: use-isnan
- message: "Unexpected space before unary operator '++'."
severity: error
data:
line: 3
column: 16
ruleId: space-unary-ops
- message: Missing semicolon.
severity: warning
data:
line: 3
column: 20
ruleId: semi
- message: "Unexpected 'else' after 'return'."
severity: warning
data:
line: 4
column: 12
ruleId: no-else-return
- message: Expected indentation of 8 space characters but found 6.
severity: warning
data:
line: 5
column: 7
ruleId: indent
- message: Expected a return value.
severity: error
data:
line: 5
column: 7
ruleId: consistent-return
- message: Missing semicolon.
severity: warning
data:
line: 5
column: 13
ruleId: semi
- message: Unnecessary semicolon.
severity: error
data:
line: 7
column: 2
ruleId: no-extra-semi
...
unix
fullOfProblems.js:1:10: 'addOne' is defined but never used [Error/no-unused-vars]
fullOfProblems.js:2:9: Use the isNaN function to compare with NaN. [Error/use-isnan]
fullOfProblems.js:3:16: Unexpected space before unary operator '++'. [Error/space-unary-ops]
fullOfProblems.js:3:20: Missing semicolon. [Warning/semi]
fullOfProblems.js:4:12: Unexpected 'else' after 'return'. [Warning/no-else-return]
fullOfProblems.js:5:7: Expected indentation of 8 space characters but found 6. [Warning/indent]
fullOfProblems.js:5:7: Expected a return value. [Error/consistent-return]
fullOfProblems.js:5:13: Missing semicolon. [Warning/semi]
fullOfProblems.js:7:2: Unnecessary semicolon. [Error/no-extra-semi]
9 problems
visualstudio
fullOfProblems.js(1,10): error no-unused-vars : 'addOne' is defined but never used
fullOfProblems.js(2,9): error use-isnan : Use the isNaN function to compare with NaN.
fullOfProblems.js(3,16): error space-unary-ops : Unexpected space before unary operator '++'.
fullOfProblems.js(3,20): warning semi : Missing semicolon.
fullOfProblems.js(4,12): warning no-else-return : Unexpected 'else' after 'return'.
fullOfProblems.js(5,7): warning indent : Expected indentation of 8 space characters but found 6.
fullOfProblems.js(5,7): error consistent-return : Expected a return value.
fullOfProblems.js(5,13): warning semi : Missing semicolon.
fullOfProblems.js(7,2): error no-extra-semi : Unnecessary semicolon.
9 problems