Difference between revisions of "Orion/ESLint"

Revision as of 12:23, 10 March 2015

Orion 5.0 moved to ESLint as the validator that ships with Orion. This page captures ongoing issues.

Rules

The following table describes all of the rules currently available in Orion and ones that we plan to add in the future.

Rules that are currently available are ~~struck out~~.

Potential Programming Problems

These rules report about problems with your code that might have undesired or incorrect results. Warnings from these rules should be addressed.

Rule	Default Severity	Available Since	Problem Message	Details
~~no-comma-dangle~~	Ignore	8.0	Trailing commas in object expressions are discouraged.	Flags trailing commas in object expressions.
~~no-cond-assign~~	Error	8.0	Expected a conditional expression and instead saw an assignment.	Flags assignment in an `if/while/do..while/for` condition.
~~no-console~~	Error	8.0	Discouraged use of console in browser-based code.	Flags the use of console in browser-based code
~~no-constant-condition~~	Error	8.0	Discouraged use of constant as a conditional expression.	Flags the use of a constant as a conditional expression
~~no-debugger~~	Warning	6.0	debugger' statement use is discouraged.
~~no-dupe-keys~~	Error	6.0	Duplicate object key '{key}'.	Flags object literals that contain the same key more than once.
~~no-empty-block~~	Warning	7.0		Flags an empty block like `if (something) { }`.
~~no-extra-semi~~	Warning	5.0	Unnecessary semicolon.
~~no-regex-spaces~~	Error	8.0	Avoid using multiple spaces in regular expressions. Use ' {${0}}' instead.	Flags regular expressions that have two or more subsequent spaces.
~~no-reserved-keys~~	Error	8.0	Reserved words should not be used as property keys.	Checks to see if a JavaScript reserved word is being used as a property key
~~no-sparse-arrays~~	Warning	8.0	Sparse array declarations should de avoided.	Flags sparse arrays with null elements
~~no-unreachable~~	Error	-	Unreachable code.	Flags statements that occur after a `return`, `throw`, etc.
~~use-isnan~~	Error	6.0	Use the isNaN function to compare with NaN.

Best Practices

These rules are not necessarily problem with your code, but are warnings that you might be doing something you probably should not be.

Rule	Default Severity	Available Since	Problem Message	Details
block-scoped-var	Error	-	'{variable}' is already defined.	Occurs when a function-scoped variable is treated as if it was block scoped. ESLint calls this error '{variable} used outside of binding context.'
~~curly~~	Ignore	6.0	Statements should be enclosed in braces.
~~eqeqeq~~	Warning	5.0	Expected '===' and saw '=='. Expected '!==' and saw '!='.
~~missing-doc~~	Ignore	5.0	"Missing documentation for function '{name}.'"	Flags missing documentation nodes on function declarations and function expressions when they appear as object properties
missing-doc-items	Ignore	-		Flags missing documentation for parameters, returns, throws, etc on function declarations and function expressions when they appear as object properties
~~no-caller~~	Error	9.0	arguments.{callee, caller} is deprecated.	Flags references to `arguments.callee` and `arguments.caller`.
~~no-eval~~	Ignore	6.0	'eval' function calls are discouraged.
~~no-fallthrough~~	Error	-	Switch case may be entered by falling through previous case. If intended, add a new comment //$FALL-THROUGH$ on the line above	Flags a fallthrough case within a `switch` statement, unless it is explicitly commented.
~~no-implied-eval~~	Ignore	6.0	Implicit 'eval' function calls are discouraged.	Flags calls to the string-argument form of `setTimeout` and `setInterval`, which implicitly perform `eval`. This rule logic was merged to be part of the no-eval rule.
~~no-iterator~~	Error	8.0	Discouraged __iterator__ property use.	Flags use of __iterator__ as an identifier name or property key.
~~no-new-array~~	Warning	6.0	Use the array literal notation [].	Flags `new Array()`.
~~no-new-func~~	Warning	6.0	The Function constructor is eval.	Flags `new Function()`.
~~no-new-object~~	Warning	6.0	Use the object literal notation {}.	Flags `new Object()`.
~~no-new-wrappers~~	Warning	6.0	Do not use {String, Number, Boolean, Math, JSON} as a constructor.	Flags `new` applied to any of those.
no-proto	Error	-	Reserved name '__proto__' should not be assigned." 'Reserved name '__proto__' should not be used as a key."
~~no-redeclare~~	Warning	5.0	'{a}' is already defined.	Usually results from having two `for` loops in the same function that share a loop variable declaration like `var i=...`.
no-self-compare	Error	-		Flags comparisons where the left- and right-hand sides are the same.
~~no-shadow~~	Warning	8.0	'{a}' is already declared in the upper scope.	Flags variables that have the same name as a variable declared in an upper scope.
~~no-shadow-global~~	Warning	9.0	'{a}' shadows a global member.	Flags variables that have the same name as a variable declared in the global scope or specified environments.
~~no-undef~~	Error	5.0	'{variable}' is not defined.	Flags references to a global variable that is not listed in a /global/ or /globals/ block. Predefined environments (eg. node, browser) can be set in the /jslint / block.
~~no-unused-params~~	Warning	-	"Parameter '{param}' is not used."	Flags parameters in function declarations / expressions if they are not being used
~~no-unused-vars~~	Warning	5.0	Function declares unused variable '{a}'.
~~no-use-before-define~~	Warning	5.0	'{a}' was used before it was defined.
no-with	Warning	-	Expected an identifier and instead saw 'with'.	Treated as fatal parse error in JSLint.
~~radix~~	Warning	8.0	Missing radix parameter.	Warns when parseInt() called without the 2nd parameter (radix).
~~throw-error~~	Warning	7.0		Flags code that throws a non-Error, eg. `throw "a problem occurred";`

Code Style

These rules are not problems in any way but will warn based on certain accepted styles for coding.

Rule	Default Severity	Available Since	Problem Message	Details
missing-nls	Ignore	-		Flags String literals that are not properly NLS'd
~~new-parens~~	Error	6.0	Missing parentheses invoking constructor.	Flags `new Whatever`
no-mixed-returns	Error	-		Flags functions that return more than one kind of item, for example returning String and Object
no-undef-init	Warning	-	It is not necessary to initialize '{variable}' to 'undefined'.
~~semi~~	Warning	5.0	Missing semicolon.

Implementing a new rule

This section explains how to implement a new linting rule. For brevity, all paths are given relative to bundles/org.eclipse.orion.client.javascript/web/ in the client repo.

First, create the tests and rule:

Create a new test file for the rule at: /eslint/tests/lib/rules/{rule-name}.js.
Link your test to the suite in /eslint/tests/load-tests.js.
Implement the actual logic for your rule in /eslint/lib/load-rules-async.js.

At this point you should run the JS bundle tests and ensure your rule works as intended. To get your rule running in the Orion product's validator, there are additional steps:

Create strings for the validation message(s) generated by your rule in /javascript/nls/root/problems.js.
Create a short string describing what your rule does in /javascript/nls/root/messages.js.
Add an entry to the orion.core.setting declaration in /javascript/plugins/javascriptPlugin.js. This allows your rule to be configured from the JS validator settings page. Make sure it references the same nameKey used in messages.js.
Add a config entry for your rule to the default ESLint config object in /javascript/validator.js.
Add your rule to the #updated() handler in /javascript/validator.js.

Reload the JS plugin, and your rule should now be configurable from the Settings page, and properly set up for translation too.

Tests

Every rule needs extensive unit tests.
Unit tests should use Mocha.

Running the tests

To run the ESLint tests as part of the main JavaScript tests suite load {orion-server-url}/javascript/js-tests/JsMochaSuite.html in your web browser.
- Click here to see the suite running on orionhub.
To run just the ESLint rule tests, load {orion-server-url}/js-tests/javascript/JsMochaSuite.html?grep=ESLint%20Rule%20Tests in your browser.
- Click here to see the suite running on orionhub.
To run just the ESLint core tests, load {orion-server-url}/js-tests/javascript/JsMochaSuite.html?grep=ESLint%20Core%20Tests in your browser.
- Click here to see the suite running on orionhub.
To run only a subset of the tests, add ?grep=ESLint%20Rule%20Tests onto the test page URL.

See Mocha usage options for more options.

User interface

~~Should we have a UI for configuring what rules are active?~~ bug 424268.
Should we try to support .eslintrc? This would be an ideal project-scope setting.
~~Should we try to honor equivalent JSLint/JSHint flags when possible? For example /*jslint eqeqeq:false */ could disable the eqeqeq rule on a per-file basis.~~
- ESLint now has its own syntax for this: /*eslint ..*/, which we are using instead.

i18n

We need to support i18n. Pre-req is bug 422278 (orion.edit.validator support for i18n).

Notice: this Wiki will be going read only early in 2024 and edits will no longer be possible. Please see: https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/wikis/Wiki-shutdown-plan for the plan.

Difference between revisions of "Orion/ESLint"

Revision as of 12:23, 10 March 2015

Contents

Rules

Potential Programming Problems

Best Practices

Code Style

Implementing a new rule

Tests

Running the tests

User interface

i18n

@@ Line 5: / Line 5: @@
 Rules that are currently available are <del>struck out</del>.
+=== Potential Programming Problems ===
+These rules report about problems with your code that might have undesired or incorrect results. Warnings from these
+rules should be addressed.
 {| class="wikitable" border="1" cellpadding="5" cellspacing="0" style="width: 100%;"
@@ Line 13: / Line 17: @@
 ! style="background:#efefef;" width=40% | Details
 |-
-!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=428433 block-scoped-var]
-| Error
-| -
-| '''{variable}' is already defined.''
-|
-* Occurs when a function-scoped variable is treated as if it was block scoped.
-* ESLint calls this error '{variable} used outside of binding context.'
-|-
-!| brace-style
-| Ignore
-| -
-| &nbsp;
-| &nbsp;
-|-
-!| camelcase
-| Ignore
-| -
-| &nbsp;
-| &nbsp;
-|-
-!| complexity
-| Ignore
-|  -
-| &nbsp;
-| &nbsp;
-|-
-!| consistent-this
-| Ignore
-|  -
-| &nbsp;
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429722 curly]</del>
-| Ignore
-| 6.0
-| ''Statements should be enclosed in braces.''
-| &nbsp;
-|-
-!| dot-notation
-| Warning
-| -
-| ''{a} is better written in dot notation.''
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 eqeqeq]</del>
-| Warning
-| 5.0
-|
-* ''Expected '===' and saw '=='.''
-* ''Expected '!==' and saw '!='.''
-| &nbsp;
-|-
-!| guard-for-in
-| Ignore
-| -
-| ''The body of a <code>for in</code> should be wrapped in an <code>if</code> statement to filter unwanted properties from the prototype.''
-| &nbsp;
-|-
-!| max-depth
-| Ignore
-| -
-| &nbsp;
-| Enforces max depth of nested blocks within a function.
-|-
-!| max-len
-| Ignore
-| -
-| ''Line is too long.''
-| Enforces a maximum line length.
-|-
-!| max-params
-| Ignore
-| -
-| &nbsp;
-| &nbsp;
-|-
-!| max-statements
-| Ignore
-| -
-| &nbsp;
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=424128 missing-doc]</del>
-| Ignore
-| 5.0
-| "Missing documentation for function '{name}.'"
-| Flags missing documentation nodes on function declarations and function expressions when they appear as object properties
-|-
-!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=424204 missing-doc-items]
-| Ignore
-| -
-|&nbsp;
-| Flags missing documentation for parameters, returns, throws, etc on function declarations and function expressions when they appear as object properties
-|-
-!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=428429 missing-nls]
-| Ignore
-| -
-| &nbsp;
-| Flags String literals that are not properly NLS'd
-|-
-!| new-cap
-| Warning
-| -
-| ''A constructor name should start with an uppercase letter.''
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429801 new-parens]</del>
-| Error
-| 6.0
-| ''Missing parentheses invoking constructor.''
-| Flags <code>new Whatever</code>
-|-
-!| no-alert
-| Ignore
-| -
-| '''{alert, confirm, prompt}' is not defined.''
-| &nbsp;
-|-
-!| no-bitwise
-| Warning
-| -
-| ''Unexpected use of '{operator}'.''
-| JSLint disallows bitwise ops by default.
-|-
-!| <del>no-caller</del>
-| Error
-| -
-| ''arguments.{callee, caller} is deprecated.''
-| Flags references to <code>arguments.callee</code> and <code>arguments.caller</code>.
-|-
-!| no-catch-shadow
-| Warning
-| -
-| '''{a}' is already defined.''
-|
-* Flags a <code>catch</code> clause's variable that shadows a variable declared in an upper scope. (In IE8 this [http://weblog.bocoup.com/the-catch-with-try-catch/ causes the upper variable to be overwritten]).
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455253 no-comma-dangle]</del>
 | Ignore
@@ Line 179: / Line 23: @@
 | Flags trailing commas in object expressions.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455250 no-cond-assign]</del>
 | Error
@@ Line 186: / Line 29: @@
 | Flags assignment in an <code>if/while/do..while/for</code> condition.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455371 no-console]</del>
 | Error
@@ Line 193: / Line 35: @@
 | Flags the use of console in browser-based code
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455680 no-constant-condition]</del>
 | Error
@@ Line 200: / Line 41: @@
 | Flags the use of a constant as a conditional expression
 |-
-!| no-control-regex
-| Ignore
-| -
-| &nbsp;
-| Flags control characters (U+0000–U+001F and U+007F) within the source argument to the RegExp constructor.
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429690 no-debugger]</del>
 | Warning
@@ Line 214: / Line 47: @@
 | &nbsp;
 |-
-!| no-delete-var
-| Warning
-| -
-| ''Deleting a local variable is discouraged.''
-| Flags an attempt to <code>delete</code> a local variable.
-|-
-!| no-div-regex
-| Warning
-| -
-| ''A regular expression literal can be confused with '/='.''
-| Flags a regex literal starting with <code>/=</code>
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=428430 no-dupe-keys]</del>
 | Error
@@ Line 235: / Line 53: @@
 | Flags object literals that contain the same key more than once.
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=439366 no-empty-block]</del>
-!| no-else-return
 | Warning
-| -
+| 7.0
 | &nbsp;
-| Flags an <code>else</code> appearing after an <code>if</code> that contains a <code>return</code>.
+| Flags an empty block like <code>if (something) { }</code>.
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=428040 no-extra-semi]</del>
-!| no-empty-class
 | Warning
-| -
+| 5.0
-| ''Empty class.''
+| ''Unnecessary semicolon.''
-| Flags an empty character class <code>[]</code> within a regular expression.
+| &nbsp;
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455391 no-regex-spaces]</del>
-!| no-empty-label
+| Error
+| 8.0
+| Avoid using multiple spaces in regular expressions. Use ' {${0}}' instead.
+| Flags regular expressions that have two or more subsequent spaces.
+|-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455354 no-reserved-keys]</del>
+| Error
+| 8.0
+| ''Reserved words should not be used as property keys.''
+| Checks to see if a JavaScript reserved word is being used as a property key
+|-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=426723 no-sparse-arrays]</del>
 | Warning
-| -
+| 8.0
-| ''Label '{a}' is not allowed on this statement.''
+| ''Sparse array declarations should de avoided.''
-| Flags a labeled statement that is not a <code>switch</code>, <code>for</code>, or <code>while</code>.
+| Flags sparse arrays with null elements
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=436986 no-unreachable]</del>
-!| <del>no-empty</del>
+| Error
-| Warning
 | -
+| ''Unreachable code.''
+| Flags statements that occur after a <code>return</code>, <code>throw</code>, etc.
+|-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429711 use-isnan]</del>
+| Error
+| 6.0
+| ''Use the isNaN function to compare with NaN.''
 | &nbsp;
-| Flags an empty block like <code>if (something) { }</code>.
 |-
+|}
-!| no-eq-null
+=== Best Practices ===
+These rules are not necessarily problem with your code, but are warnings that you might be doing something
+you probably should not be.
+{| class="wikitable" border="1" cellpadding="5" cellspacing="0" style="width: 100%;"
+! style="background:#efefef;" width=5% | Rule
+! style="background:#efefef;" width=5% | Default Severity
+! style="background:#efefef;" width=5% | Available Since
+! style="background:#efefef;" width=40%| Problem Message
+! style="background:#efefef;" width=40% | Details
+|-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=428433 block-scoped-var]
 | Error
 | -
-| ''Use '===' to compare with 'null'.''
+| '''{variable}' is already defined.''
-| &nbsp;
+|
+* Occurs when a function-scoped variable is treated as if it was block scoped.
+* ESLint calls this error '{variable} used outside of binding context.'
 |-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429702 no-eval]</del>
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429722 curly]</del>
 | Ignore
 | 6.0
-| '''eval' function calls are discouraged.''
+| ''Statements should be enclosed in braces.''
 | &nbsp;
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 eqeqeq]</del>
-!| no-ex-assign
 | Warning
-| -
+| 5.0
-| ''Do not assign to the exception parameter.''
+|
+* ''Expected '===' and saw '=='.''
+* ''Expected '!==' and saw '!='.''
 | &nbsp;
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=424128 missing-doc]</del>
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=428040 no-extra-semi]</del>
+| Ignore
-| Warning
 | 5.0
-| ''Unnecessary semicolon.''
+| "Missing documentation for function '{name}.'"
-| &nbsp;
+| Flags missing documentation nodes on function declarations and function expressions when they appear as object properties
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=424204 missing-doc-items]
-!| no-extra-strict
+| Ignore
-| Warning
 | -
+|&nbsp;
+| Flags missing documentation for parameters, returns, throws, etc on function declarations and function expressions when they appear as object properties
+|-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=460976 no-caller]</del>
+| Error
+| 9.0
+| ''arguments.{callee, caller} is deprecated.''
+| Flags references to <code>arguments.callee</code> and <code>arguments.caller</code>.
+|-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429702 no-eval]</del>
+| Ignore
+| 6.0
+| '''eval' function calls are discouraged.''
 | &nbsp;
-| Flags <code>"use strict"</code> on a function when the entire Program is already in strict mode.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429815 no-fallthrough]</del>
 | Error
@@ Line 305: / Line 162: @@
 | Flags a fallthrough case within a <code>switch</code> statement, unless it is explicitly commented.
 |-
-!| no-floating-decimal
-| Warning
-| -
-| ''A {leading, trailing} decimal point can be confused with a dot: '{n}'.''
-| Flags numeric literals that have a leading or trailing decimal point.
-|-
-!| no-func-assign
-| Warning
-| -
-| &nbsp;
-| Flags assignment to a variable that's already bound to a <code>FunctionExpression</code>.
-|-
-!| no-global-strict
-| Warning
-| -
-| &nbsp;
-| Flags <code>"use strict"</code> applied to the entire Program.
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429707 no-implied-eval]</del>
 | Ignore
@@ Line 333: / Line 168: @@
 | Flags calls to the string-argument form of <code>setTimeout</code> and <code>setInterval</code>, which implicitly perform <code>eval</code>. This rule logic was merged to be part of the <b>no-eval</b> rule.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455643 no-iterator]</del>
 | Error
@@ Line 340: / Line 174: @@
 | Flags use of __iterator__ as an identifier name or property key.
 |-
-!| no-label-var
-| Error
-| -
-| '''{label}' is already defined.''
-| Flags labels that collide with an identifier.
-|-
-!| no-loop-func
-| Error
-| -
-| ''Don't make functions within a loop.''
-| &nbsp;
-|-
-!| no-mixed-requires
-| Ignore
-| -
-| &nbsp;
-| Flags Node.js <code>require()</code>s that mix different types of requires (core, module, file, computed).
-|-
-!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=425200 no-mixed-returns]
-| Error
-| -
-| &nbsp;
-| Flags functions that return more than one kind of item, for example returning String and Object
-|-
-!| no-multi-str
-| Warning
-| -
-| &nbsp;
-| Flags use of ES5 multiline string literals.
-|-
-!| no-native-reassign
-| Warning
-| -
-|
-* ''Read only.''
-* ''Bad assignment.'' (if assigning to <code>undefined</code>)
-| Flags an attempt to reassign a native object like <code>Math</code>, Array, <code>undefined</code>, etc.
-|-
-!| no-negated-in-lhs
-| Warning
-| -
-| &nbsp;
-|
-* Flags a unary <code>!</code> operator applied to the LHS of an in statement, which negates the LHS, not the <code>in</code>.
-* Eg. <code>(!"key" in {key: 1})</code> (which always evaluates to false), will be flagged.
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429817 no-new-array]</del>
 | Warning
-| -
+| 6.0
 | ''Use the array literal notation [].''
 | Flags <code>new Array()</code>.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429817 no-new-func]</del>
 | Warning
-| -
+| 6.0
 | ''The Function constructor is eval.''
 | Flags <code>new Function()</code>.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429817 no-new-object]</del>
 | Warning
-| -
+| 6.0
 | ''Use the object literal notation {}.''
 | Flags <code>new Object()</code>.
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429817 no-new-wrappers]</del>
 | Warning
-| -
+| 6.0
 | ''Do not use {String, Number, Boolean, Math, JSON} as a constructor.''
 | Flags <code>new</code> applied to any of those.
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=461848 no-proto]
-!| no-new
-| Error
-| -
-| ''Do not use 'new' for side effects.''
-| Flags uses of <code>new</code> operator in an expression that is not assigned to anything.
-|-
-!| no-obj-calls
-| Warning
-| -
-| ''Math is not a function..''
-|
-* Flags attempts to call object properties of the global object (<code>Math</code>, <code>JSON</code>) as a function, like <code>Math()</code>.
-|-
-!| no-octal-escape
-| Warning
-| -
-| ''Bad escapement.''
-| Flags octal escapes in strings, for example <code>var x = "Copyright \251";</code>
-|-
-!| no-octal
-| Warning
-| -
-| ''Don't use extra leading zeros '{n}'.''
-| Flags number literals that begin with leading 0s, which indicate a (probably accidental) octal literal.
-|-
-!| no-plusplus
-| Warning
-| -
-|
-* ''Unexpected use of '++'''
-* ''Unexpected use of '--'''
-| &nbsp;
-|-
-!| no-proto
 | Error
 | -
@@ Line 468: / Line 206: @@
 | &nbsp;
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 no-redeclare]</del>
 | Warning
@@ Line 475: / Line 212: @@
 | Usually results from having two <code>for</code> loops in the same function that share a loop variable declaration like <code>var i=...</code>.
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=461850 no-self-compare]
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455391 no-regex-spaces]</del>
-| Error
-| 8.0
-| Avoid using multiple spaces in regular expressions. Use ' {${0}}' instead.
-| Flags regular expressions that have two or more subsequent spaces.
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=455354 no-reserved-keys]</del>
-| Error
-| 8.0
-| ''Reserved words should not be used as property keys.''
-| Checks to see if a JavaScript reserved word is being used as a property key
-|-
-!| no-return-assign
-| Warning
-| -
-| &nbsp;
-|
-* Prevents assignment in a <code>return</code> statement.
-* Unsupported by JSLint, although JSLint does require parens around a return-assignment, eg: <code>return (x = 2);</code>
-|-
-!| no-script-url
-| Warning
-| -
-| &nbsp;
-|
-* Flags string literals beginning with <code>javascript:</code>. (Script URLs are a form of <code>eval</code>.)
-|-
-!| no-self-compare
 | Error
 | -
@@ Line 513: / Line 218: @@
 | Flags comparisons where the left- and right-hand sides are the same.
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=438319 no-shadow]</del>
-!!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=438319 no-shadow]</del>
 | Warning
 | 8.0
@@ Line 520: / Line 224: @@
 | Flags variables that have the same name as a variable declared in an upper scope.
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=461321 no-shadow-global]</del>
-!| no-spaced-func
-| Ignore
-| -
-| ''Unnecessary space in function call.''
-| Report on excess space in a function call, for example <code>myFunc ();</code> or <code>new MyObj ();</code>
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=426723 no-sparse-arrays]</del>
 | Warning
-| 8.0
+| 9.0
-| ''Sparse array declarations should de avoided.''
+| '''{a}' shadows a global member.''
-| Flags sparse arrays with null elements
+| Flags variables that have the same name as a variable declared in the global scope or specified environments.
 |-
-!| no-sync
-| Ignore
-| -
-| ''Unexpected sync method: '{a}'.''
-|
-* Flags Node.js's synchronous I/O methods.
-* The '''stupid''' option is supported only in newer versions of JSLint (not Orion's).
-|-
-!| no-ternary
-| Ignore
-| -
-| &nbsp;
-| Flags any use of the ternary operator <code>cond ? thenExpr : elseExpr</code>
-|-
-!| no-undef-init
-| Warning
-| -
-| ''It is not necessary to initialize '{variable}' to 'undefined'.''
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=427310 no-unused-params]</del>
-| Warning
-| -
-| "Parameter '{param}' is not used."
-| Flags parameters in function declarations / expressions if they are not being used
-|-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 no-undef]</del>
 | Error
@@ Line 573: / Line 238: @@
 * Predefined environments (eg. '''node''', '''browser''') can be set in the /*jslint */ block.
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=427310 no-unused-params]</del>
-!| no-underscore-dangle
-| Ignore
-| -
-| ''Dangling '_'''
-| &nbsp;
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=436986 no-unreachable]</del>
-| Error
-| -
-| ''Unreachable code.''
-| Flags statements that occur after a <code>return</code>, <code>throw</code>, etc.
-|-
-!| no-unused-expressions
 | Warning
 | -
-| ''Expected an assignment or function call and instead saw an expression.''
+| "Parameter '{param}' is not used."
-| Flags expressions that appear in a statement context and don't cause side effects.
+| Flags parameters in function declarations / expressions if they are not being used
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 no-unused-vars]</del>
-!| <deL>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 no-unused-vars]</del>
 | Warning
 | 5.0
@@ Line 601: / Line 250: @@
 | &nbsp;
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=414779 no-use-before-define]</del>
 | Warning
@@ Line 608: / Line 256: @@
 | &nbsp;
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=461854 no-with]
-!| no-with
 | Warning
 | -
@@ Line 615: / Line 262: @@
 | Treated as fatal parse error in JSLint.
 |-
+!| <del>[http://git.eclipse.org/c/orion/org.eclipse.orion.client.git/commit/?id=f61bdaf06ac2f40eaca4daed39520cd60c41f5f3 radix]</del>
-!| no-wrap-func
+| Warning
-| Ignore
+| 8.0
-| -
+| ''Missing radix parameter.''
-| ''Do not wrap function literals in parens unless they are to be immediately invoked.''
+| Warns when parseInt() called without the 2nd parameter (radix).
-| Flags a parenthesized function literal that is not immediately invoked, eg. <code>(function fun(){})</code>
 |-
+!| <del>[http://git.eclipse.org/c/orion/org.eclipse.orion.client.git/commit/?id=6e517847ef0742b090130748fb9a0329d33e16bf throw-error]</del>
-!| object-prototype-external
 | Warning
-| -
+| 7.0
 | &nbsp;
-| Flags calls to methods of <code>Object.prototype</code> that rely on the prototype chain. For example this code should be flagged:
+| Flags code that throws a non-Error, eg. <code>throw "a problem occurred";</code>
-<source lang="javascript" line="line">
-foo.hasOwnProperty("bar")
-</source>
-Example (1) is [https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty?redirectlocale=en-US&redirectslug=JavaScript%2FReference%2FGlobal_Objects%2FObject%2FhasOwnProperty#hasOwnProperty_as_a_property unsafe], as <code>foo</code> may have a property named <code>hasOwnProperty</code>, or have been constructed via <code>Object.create(null)</code>.
-As for this:
-<source lang="javascript" line="line" start="2">
-Object.hasOwnProperty.call(foo, "bar")
-</source>
-Example (2) technically relies on the prototype chain as well: the hasOwnProperty method is defined on Object.prototype, not Object. Object inherits the methods of Object.prototype [http://stackoverflow.com/questions/14817826/difference-between-an-object-and-its-prototype/14817913#14817913 through its prototype chain]. However (2) is unlikely to fail, as sane JavaScript programs will not modify the global objects' prototypes. If we choose to flag (2), it should only be for style.
 |-
+|}
-!| one-var
+=== Code Style ===
-| Warning
+These rules are not problems in any way but will warn based on certain accepted styles for coding.
-| -
-| ''Too many var statements.''
-| Allows only 1 <code>var</code> statement per function.
-|-
-!| quote-props
+{| class="wikitable" border="1" cellpadding="5" cellspacing="0" style="width: 100%;"
-| Warning
+! style="background:#efefef;" width=5% | Rule
-| -
+! style="background:#efefef;" width=5% | Default Severity
-| &nbsp;
+! style="background:#efefef;" width=5% | Available Since
-| Requires object literal keys to be quoted with " or '.
+! style="background:#efefef;" width=40%| Problem Message
+! style="background:#efefef;" width=40% | Details
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=428429 missing-nls]
-!| quotes
 | Ignore
 | -
 | &nbsp;
-| Flags any use of single or double quote marks, depending on setting.
+| Flags String literals that are not properly NLS'd
 |-
+!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429801 new-parens]</del>
-!| <del>radix</del>
+| Error
-| Warning
+| 6.0
+| ''Missing parentheses invoking constructor.''
+| Flags <code>new Whatever</code>
+|-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=425200 no-mixed-returns]
+| Error
 | -
-| ''Missing radix parameter.''
+| &nbsp;
-| Warns when parseInt() called without the 2nd parameter (radix).
+| Flags functions that return more than one kind of item, for example returning String and Object
 |-
+!| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=461852 no-undef-init]
-!| regex-spaces
 | Warning
 | -
-| ''Spaces are hard to count. Use {n}.''
+| ''It is not necessary to initialize '{variable}' to 'undefined'.''
 | &nbsp;
 |-
 !| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=427930 semi]</del>
 | Warning
@@ Line 684: / Line 316: @@
 | &nbsp;
 |-
-!| strict
-| Ignore
-| -
-| &nbsp;
-| Flags any code that lacks the <code>"use strict"</code> pragma.
-|-
-!| <del>[http://git.eclipse.org/c/orion/org.eclipse.orion.client.git/commit/?id=6e517847ef0742b090130748fb9a0329d33e16bf throw-error]</del>
-| Warning
-| 7.0
-| &nbsp;
-| Flags code that throws a non-Error, eg. <code>throw "a problem occurred";</code>
-|-
-!| <del>[https://bugs.eclipse.org/bugs/show_bug.cgi?id=429711 use-isnan]</del>
-| Error
-| 6.0
-| ''Use the isNaN function to compare with NaN.''
-| &nbsp;
-|-
-!| wrap-iife
-| Ignore
-| -
-|
-* ''Wrap the entire immediate function invocation in parens.''
-* ''Move the invocation into the parens that contain the function.''
-| Flags missing parens on immediately-invoked functions, eg. <code>function(){ console.log('hi'); }();</code>
-|-
-!| wrap-regex
-| Warning
-| -
-| ''Wrap the /regexp/ literal in parens to disambiguate the slash operator.''
-| &nbsp;
-|-
 |}
-=== Implementing a new rule ===
+== Implementing a new rule ==
 ''This section explains how to implement a new linting rule. For brevity, all paths are given relative to <tt>bundles/org.eclipse.orion.client.javascript/web/</tt> in the client repo.''

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Difference between revisions of "Orion/ESLint"

Revision as of 12:23, 10 March 2015

Contents

Rules

Potential Programming Problems

Best Practices

Code Style

Implementing a new rule

Tests

Running the tests

User interface

i18n