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Difference between revisions of "Orion/ESLint"
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|- | |- | ||
− | !| [ | + | !| [no-comma-dangle] |
| Warning | | Warning | ||
| - | | - | ||
Line 180: | Line 180: | ||
|- | |- | ||
− | !| no-cond-assign | + | !| [https://bugs.eclipse.org/bugs/show_bug.cgi?id=455250 no-cond-assign] |
| Ignore | | Ignore | ||
| - | | - | ||
Line 498: | Line 498: | ||
| ''Unnecessary space in function call.'' | | ''Unnecessary space in function call.'' | ||
| Report on excess space in a function call, for example <code>myFunc ();</code> or <code>new MyObj ();</code> | | 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 | ||
+ | | - | ||
+ | | ''Sparse array declarations should de avoided.'' | ||
+ | | Flags sparse arrays with null elements | ||
|- | |- | ||
Revision as of 12:36, 15 December 2014
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.
Rule | Default Severity | Available Since | Problem Message | Details |
---|---|---|---|---|
block-scoped-var | Error | - | '{variable}' is already defined. |
|
brace-style | Ignore | - | ||
camelcase | Ignore | - | ||
complexity | Ignore | - | ||
consistent-this | Ignore | - | ||
|
Ignore | 6.0 | Statements should be enclosed in braces. | |
dot-notation | Warning | - | {a} is better written in dot notation. | |
|
Warning | 5.0 |
|
|
guard-for-in | Ignore | - | The body of a for in should be wrapped in an if statement to filter unwanted properties from the prototype.
|
|
max-depth | Ignore | - | Enforces max depth of nested blocks within a function. | |
max-len | Ignore | - | Line is too long. | Enforces a maximum line length. |
max-params | Ignore | - | ||
max-statements | Ignore | - | ||
|
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 | |
missing-nls | Ignore | - | Flags String literals that are not properly NLS'd | |
new-cap | Warning | - | A constructor name should start with an uppercase letter. | |
|
Error | 6.0 | Missing parentheses invoking constructor. | Flags new Whatever
|
no-alert | Ignore | - | '{alert, confirm, prompt}' is not defined. | |
no-bitwise | Warning | - | Unexpected use of '{operator}'. | JSLint disallows bitwise ops by default. |
|
Error | - | arguments.{callee, caller} is deprecated. | Flags references to arguments.callee and arguments.caller .
|
no-catch-shadow | Warning | - | '{a}' is already defined. |
|
[no-comma-dangle] | Warning | - | Unexpected comma. | Flags trailing commas in object literals and array declarations. |
no-cond-assign | Ignore | - | Flags assignment in an if/while/do..while/for condition.
| |
no-console | Ignore | - | ||
no-control-regex | Ignore | - | Flags control characters (U+0000–U+001F and U+007F) within the source argument to the RegExp constructor. | |
|
Warning | 6.0 | debugger' statement use is discouraged. | |
no-delete-var | Warning | - | Deleting a local variable is discouraged. | Flags an attempt to delete a local variable.
|
no-div-regex | Warning | - | A regular expression literal can be confused with '/='. | Flags a regex literal starting with /=
|
|
Error | 6.0 | Duplicate object key '{key}'. | Flags object literals that contain the same key more than once. |
no-else-return | Warning | - | Flags an else appearing after an if that contains a return .
| |
no-empty-class | Warning | - | Empty class. | Flags an empty character class [] within a regular expression.
|
no-empty-label | Warning | - | Label '{a}' is not allowed on this statement. | Flags a labeled statement that is not a switch , for , or while .
|
|
Warning | - | Flags an empty block like if (something) { } .
| |
no-eq-null | Error | - | Use '===' to compare with 'null'. | |
|
Ignore | 6.0 | 'eval' function calls are discouraged. | |
no-ex-assign | Warning | - | Do not assign to the exception parameter. | |
|
Warning | 5.0 | Unnecessary semicolon. | |
|
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-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 | - | Flags assignment to a variable that's already bound to a FunctionExpression .
| |
no-global-strict | Warning | - | Flags "use strict" applied to the entire Program.
| |
|
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 | - | Reserved name '__iterator__'. | 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. | |
no-mixed-requires | Ignore | - | Flags Node.js require() s that mix different types of requires (core, module, file, computed).
| |
no-mixed-returns | Error | - | Flags functions that return more than one kind of item, for example returning String and Object | |
no-multi-str | Warning | - | Flags use of ES5 multiline string literals. | |
no-native-reassign | Warning | - |
|
Flags an attempt to reassign a native object like Math , Array, undefined , etc.
|
no-negated-in-lhs | Warning | - |
| |
|
Warning | - | Use the array literal notation []. | Flags new Array() .
|
|
Warning | - | The Function constructor is eval. | Flags new Function() .
|
|
Warning | - | Use the object literal notation {}. | Flags new Object() .
|
|
Warning | - | Do not use {String, Number, Boolean, Math, JSON} as a constructor. | Flags new applied to any of those.
|
no-new | Error | - | Do not use 'new' for side effects. | Flags uses of new operator in an expression that is not assigned to anything.
|
no-obj-calls | Warning | - | Math is not a function.. |
|
no-octal-escape | Warning | - | Bad escapement. | Flags octal escapes in strings, for example var x = "Copyright \251";
|
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 | - |
|
|
no-proto | Error | - |
|
|
|
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-return-assign | Warning | - |
| |
no-script-url | Warning | - |
| |
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-spaced-func | Ignore | - | Unnecessary space in function call. | Report on excess space in a function call, for example myFunc (); or new MyObj ();
|
|
Warning | - | Sparse array declarations should de avoided. | Flags sparse arrays with null elements |
no-sync | Ignore | - | Unexpected sync method: '{a}'. |
|
no-ternary | Ignore | - | Flags any use of the ternary operator cond ? thenExpr : elseExpr
| |
no-undef-init | Warning | - | It is not necessary to initialize '{variable}' to 'undefined'. | |
|
Warning | - | "Parameter '{param}' is not used." | Flags parameters in function declarations / expressions if they are not being used |
|
Error | 5.0 | '{variable}' is not defined. |
|
no-underscore-dangle | Ignore | - | Dangling '_' | |
|
Error | - | Unreachable code. | Flags statements that occur after a return , throw , etc.
|
no-unused-expressions | Warning | - | Expected an assignment or function call and instead saw an expression. | Flags expressions that appear in a statement context and don't cause side effects. |
|
Warning | 5.0 | Function declares unused variable '{a}'. | |
|
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. |
no-wrap-func | Ignore | - | Do not wrap function literals in parens unless they are to be immediately invoked. | Flags a parenthesized function literal that is not immediately invoked, eg. (function fun(){})
|
object-prototype-external | Warning | - | Flags calls to methods of Object.prototype that rely on the prototype chain. For example this code should be flagged:
Example (1) is unsafe, as As for this:
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 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 | Warning | - | Too many var statements. | Allows only 1 var statement per function.
|
quote-props | Warning | - | Requires object literal keys to be quoted with " or '. | |
quotes | Ignore | - | Flags any use of single or double quote marks, depending on setting. | |
|
Warning | - | Missing radix parameter. | Warns when parseInt() called without the 2nd parameter (radix). |
regex-spaces | Warning | - | Spaces are hard to count. Use {n}. | |
|
Warning | 5.0 | Missing semicolon. | |
strict | Ignore | - | Flags any code that lacks the "use strict" pragma.
| |
|
Warning | 7.0 | Flags code that throws a non-Error, eg. throw "a problem occurred";
| |
unnecessary-strict | Warning | - | Flags "use strict" on a function when the entire Program is already in strict mode.
| |
|
Error | 6.0 | Use the isNaN function to compare with NaN. | |
wrap-iife | Ignore | - |
|
Flags missing parens on immediately-invoked functions, eg. function(){ console.log('hi'); }();
|
wrap-regex | Warning | - | Wrap the /regexp/ literal in parens to disambiguate the slash operator. |
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
- Load {orion-server-url}/eslint/tests/eslintTests.html in your web browser. For example, here are the tests running against the eslint deployed on orionhub.org: https://orionhub.org/eslint/tests/eslintTests.html
- To run the complete JS bundle test suite, use {orion-server-url}/js-tests/javascript/JsMochaSuite.html, eg: https://orionhub.org/js-tests/javascript/JsMochaSuite.html
- To run only a subset of the tests, add ?grep=someTestName 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.
- ESLint now has its own syntax for this:
i18n
We need to support i18n. Pre-req is bug 422278 (orion.edit.validator support for i18n).