While ESLint is designed to be run on the command line, it’s possible to use ESLint programmatically through the Node.js API. The purpose of the Node.js API is to allow plugin and tool authors to use the ESLint functionality directly, without going through the command line interface.
Note: Use undocumented parts of the API at your own risk. Only those parts that are specifically mentioned in this document are approved for use and will remain stable and reliable. Anything left undocumented is unstable and may change or be removed at any point.
The ESLint class is the primary class to use in Node.js applications.
This class depends on the Node.js fs module and the file system, so you cannot use it in browsers. If you want to lint code on browsers, use the Linter class instead.
Here’s a simple example of using the ESLint class:
const { ESLint } = require("eslint");
(async function main() {
// 1. Create an instance.
const eslint = new ESLint();
// 2. Lint files.
const results = await eslint.lintFiles(["lib/**/*.js"]);
// 3. Format the results.
const formatter = await eslint.loadFormatter("stylish");
const resultText = formatter.format(results);
// 4. Output it.
console.log(resultText);
})().catch((error) => {
process.exitCode = 1;
console.error(error);
});
And here is an example that autofixes lint problems:
const { ESLint } = require("eslint");
(async function main() {
// 1. Create an instance with the `fix` option.
const eslint = new ESLint({ fix: true });
// 2. Lint files. This doesn't modify target files.
const results = await eslint.lintFiles(["lib/**/*.js"]);
// 3. Modify the files with the fixed code.
await ESLint.outputFixes(results);
// 4. Format the results.
const formatter = await eslint.loadFormatter("stylish");
const resultText = formatter.format(results);
// 5. Output it.
console.log(resultText);
})().catch((error) => {
process.exitCode = 1;
console.error(error);
});
const eslint = new ESLint(options);
Create a new ESLint instance.
The ESLint constructor takes an options object. If you omit the options object then it uses default values for all options. The options object has the following properties.
options.cwd (string)process.cwd(). The working directory. This must be an absolute path.options.errorOnUnmatchedPattern (boolean)true. Unless set to false, the eslint.lintFiles() method will throw an error when no target files are found.options.extensions (string[] | null)null. If you pass directory paths to the eslint.lintFiles() method, ESLint checks the files in those directories that have the given extensions. For example, when passing the src/ directory and extensions is [".js", ".ts"], ESLint will lint *.js and *.ts files in src/. If extensions is null, ESLint checks *.js files and files that match overrides[].files patterns in your configuration.eslint.lintFiles() method. If you pass glob patterns like lib/**/*, ESLint will lint all files matching the glob pattern regardless of extension.options.globInputPaths (boolean)true. If false is present, the eslint.lintFiles() method doesn’t interpret glob patterns.options.ignore (boolean)true. If false is present, the eslint.lintFiles() method doesn’t respect .eslintignore files or ignorePatterns in your configuration.options.ignorePath (string | null)null. The path to a file ESLint uses instead of $CWD/.eslintignore. If a path is present and the file doesn’t exist, this constructor will throw an error.options.allowInlineConfig (boolean)true. If false is present, ESLint suppresses directive comments in source code. If this option is false, it overrides the noInlineConfig setting in your configurations.options.baseConfig (ConfigData | null)null. Configuration object, extended by all configurations used with this instance. You can use this option to define the default settings that will be used if your configuration files don’t configure it.options.overrideConfig (ConfigData | null)null. Configuration object, overrides all configurations used with this instance. You can use this option to define the settings that will be used even if your configuration files configure it.options.overrideConfigFile (string | null)null. The path to a configuration file, overrides all configurations used with this instance. The options.overrideConfig option is applied after this option is applied.options.plugins (Record<string, Plugin> | null)null. The plugin implementations that ESLint uses for the plugins setting of your configuration. This is a map-like object. Those keys are plugin IDs and each value is implementation.options.reportUnusedDisableDirectives ("error" | "warn" | "off" | null)null. The severity to report unused eslint-disable directives. If this option is a severity, it overrides the reportUnusedDisableDirectives setting in your configurations.options.resolvePluginsRelativeTo (string | null)null. The path to a directory where plugins should be resolved from. If null is present, ESLint loads plugins from the location of the configuration file that contains the plugin setting. If a path is present, ESLint loads all plugins from there.options.rulePaths (string[])[]. An array of paths to directories to load custom rules from.options.useEslintrc (boolean)true. If false is present, ESLint doesn’t load configuration files (.eslintrc.* files). Only the configuration of the constructor options is valid.options.fix (boolean | (message: LintMessage) => boolean)false. If true is present, the eslint.lintFiles() and eslint.lintText() methods work in autofix mode. If a predicate function is present, the methods pass each lint message to the function, then use only the lint messages for which the function returned true.options.fixTypes (("directive" | "problem" | "suggestion" | "layout")[] | null)null. The types of the rules that the eslint.lintFiles() and eslint.lintText() methods use for autofix.options.cache (boolean)false. If true is present, the eslint.lintFiles() method caches lint results and uses it if each target file is not changed. Please mind that ESLint doesn’t clear the cache when you upgrade ESLint plugins. In that case, you have to remove the cache file manually. The eslint.lintText() method doesn’t use caches even if you pass the options.filePath to the method.options.cacheLocation (string).eslintcache. The eslint.lintFiles() method writes caches into this file.options.cacheStrategy (string)"metadata". Strategy for the cache to use for detecting changed files. Can be either "metadata" or "content".const results = await eslint.lintFiles(patterns);
This method lints the files that match the glob patterns and then returns the results.
patterns (string | string[])Promise<LintResult[]>)const results = await eslint.lintText(code, options);
This method lints the given source code text and then returns the results.
By default, this method uses the configuration that applies to files in the current working directory (the cwd constructor option). If you want to use a different configuration, pass options.filePath, and ESLint will load the same configuration that eslint.lintFiles() would use for a file at options.filePath.
If the options.filePath value is configured to be ignored, this method returns an empty array. If the options.warnIgnored option is set along with the options.filePath option, this method returns a LintResult object. In that case, the result may contain a warning that indicates the file was ignored.
The second parameter options is omittable.
code (string)options.filePath (string)result.filePath becomes the string "<text>".options.warnIgnored (boolean)true is present and the options.filePath is a file ESLint should ignore, this method returns a lint result contains a warning message.Promise<LintResult[]>)eslint.lintFiles() method similar.const results = await eslint.lintFiles(patterns);
const rulesMeta = eslint.getRulesMetaForResults(results);
This method returns an object containing meta information for each rule that triggered a lint error in the given results.
results (LintResult[])ESLint#lintFiles() or ESLint#lintText().Object)results and whose property values are the rule’s meta information (if available).const config = await eslint.calculateConfigForFile(filePath);
This method calculates the configuration for a given file, which can be useful for debugging purposes.
extends and overrides settings into the top level configuration.parser setting to absolute paths.plugins setting to align short names. (e.g., eslint-plugin-foo → foo)processor setting if a legacy file extension processor is matched.env setting to the globals and parserOptions settings, so the result object contains the env setting as is.filePath (string)overrides setting.Promise<Object>)const isPathIgnored = await eslint.isPathIgnored(filePath);
This method checks if a given file is ignored by your configuration.
filePath (string)Promise<boolean>)true.const formatter = await eslint.loadFormatter(nameOrPath);
This method loads a formatter. Formatters convert lint results to a human- or machine-readable string.
nameOrPath (string | undefined)undefined. In this case, loads the "stylish" built-in formatter."foo" will load eslint-formatter-foo."@foo" will load @foo/eslint-formatter."@foo/bar" will load @foo/eslint-formatter-bar./) in order to distinguish if it’s a path or not. For example, start with ./.Promise<LoadedFormatter>)const version = ESLint.version;
The version string of ESLint. E.g. "7.0.0".
This is a static property.
await ESLint.outputFixes(results);
This method writes code modified by ESLint’s autofix feature into its respective file. If any of the modified files don’t exist, this method does nothing.
This is a static method.
results (LintResult[])Promise<void>)const filteredResults = ESLint.getErrorResults(results);
This method copies the given results and removes warnings. The returned value contains only errors.
This is a static method.
results (LintResult[])LintResult[])The LintResult value is the information of the linting result of each file. The eslint.lintFiles() and eslint.lintText() methods return it. It has the following properties:
filePath (string)"<text>" if the file path is unknown (when you didn’t pass the options.filePath option to the eslint.lintText() method).messages (LintMessage[])suppressedMessages (SuppressedLintMessage[])fixableErrorCount (number)fix constructor option.fixableWarningCount (number)fix constructor option.errorCount (number)fatalErrorCount (number)warningCount (number)output (string | undefined)source (string | undefined)output property exists.usedDeprecatedRules ({ ruleId: string; replacedBy: string[] }[])The LintMessage value is the information of each linting error. The messages property of the LintResult type contains it. It has the following properties:
ruleId (string | null)null.severity (1 | 2)1 means warning and 2 means error.fatal (boolean | undefined)true if this is a fatal error unrelated to a rule, like a parsing error.message (string)line (number | undefined)column (number | undefined)endLine (number | undefined)endColumn (number | undefined)fix (EditInfo | undefined)suggestions ({ desc: string; fix: EditInfo }[] | undefined)The SuppressedLintMessage value is the information of each suppressed linting error. The suppressedMessages property of the LintResult type contains it. It has the following properties:
ruleId (string | null)ruleId in LintMessage type.severity (1 | 2)severity in LintMessage type.fatal (boolean | undefined)fatal in LintMessage type.message (string)message in LintMessage type.line (number | undefined)line in LintMessage type.column (number | undefined)column in LintMessage type.endLine (number | undefined)endLine in LintMessage type.endColumn (number | undefined)endColumn in LintMessage type.fix (EditInfo | undefined)fix in LintMessage type.suggestions ({ desc: string; fix: EditInfo }[] | undefined)suggestions in LintMessage type.suppressions ({ kind: string; justification: string}[])The EditInfo value is information to edit text. The fix and suggestions properties of LintMessage type contain it. It has following properties:
range ([number, number])text (string)This edit information means replacing the range of the range property by the text property value. It’s like sourceCodeText.slice(0, edit.range[0]) + edit.text + sourceCodeText.slice(edit.range[1]). Therefore, it’s an add if the range[0] and range[1] property values are the same value, and it’s removal if the text property value is empty string.
The LoadedFormatter value is the object to convert the LintResult objects to text. The eslint.loadFormatter() method returns it. It has the following method:
format ((results: LintResult[], resultsMeta: ResultsMeta) => string | Promise<string>)resultsMeta is an object that will contain a maxWarningsExceeded object if --max-warnings was set and the number of warnings exceeded the limit. The maxWarningsExceeded object will contain two properties: maxWarnings, the value of the --max-warnings option, and foundWarnings, the number of lint warnings.The SourceCode type represents the parsed source code that ESLint executes on. It’s used internally in ESLint and is also available so that already-parsed code can be used. You can create a new instance of SourceCode by passing in the text string representing the code and an abstract syntax tree (AST) in ESTree format (including location information, range information, comments, and tokens):
const SourceCode = require("eslint").SourceCode;
const code = new SourceCode("var foo = bar;", ast);
The SourceCode constructor throws an error if the AST is missing any of the required information.
The SourceCode constructor strips Unicode BOM. Please note the AST also should be parsed from stripped text.
const SourceCode = require("eslint").SourceCode;
const code = new SourceCode("\uFEFFvar foo = bar;", ast);
assert(code.hasBOM === true);
assert(code.text === "var foo = bar;");
This is a static function on SourceCode that is used to split the source code text into an array of lines.
const SourceCode = require("eslint").SourceCode;
const code = "var a = 1;\nvar b = 2;"
// split code into an array
const codeLines = SourceCode.splitLines(code);
/*
Value of codeLines will be
[
"var a = 1;",
"var b = 2;"
]
*/
The Linter object does the actual evaluation of the JavaScript code. It doesn’t do any filesystem operations, it simply parses and reports on the code. In particular, the Linter object does not process configuration objects or files. Unless you are working in the browser, you probably want to use the ESLint class instead.
The Linter is a constructor, and you can create a new instance by passing in the options you want to use. The available options are:
cwd - Path to a directory that should be considered as the current working directory. It is accessible to rules by calling context.getCwd() (see The Context Object). If cwd is undefined, it will be normalized to process.cwd() if the global process object is defined (for example, in the Node.js runtime) , or undefined otherwise.For example:
const Linter = require("eslint").Linter;
const linter1 = new Linter({ cwd: 'path/to/project' });
const linter2 = new Linter();
In this example, rules run on linter1 will get path/to/project when calling context.getCwd(). Those run on linter2 will get process.cwd() if the global process object is defined or undefined otherwise (e.g. on the browser https://eslint.org/demo).
The most important method on Linter is verify(), which initiates linting of the given text. This method accepts three arguments:
code - the source code to lint (a string or instance of SourceCode).config - a configuration object that has been processed and normalized by ESLint using eslintrc files and/or other configuration arguments. ESLint#lintFiles() or ESLint#lintText() instead.options - (optional) Additional options for this run. filename - (optional) the filename to associate with the source code.preprocess - (optional) A function that Processors in Plugins documentation describes as the preprocess method.postprocess - (optional) A function that Processors in Plugins documentation describes as the postprocess method.filterCodeBlock - (optional) A function that decides which code blocks the linter should adopt. The function receives two arguments. The first argument is the virtual filename of a code block. The second argument is the text of the code block. If the function returned true then the linter adopts the code block. If the function was omitted, the linter adopts only *.js code blocks. If you provided a filterCodeBlock function, it overrides this default behavior, so the linter doesn’t adopt *.js code blocks automatically.disableFixes - (optional) when set to true, the linter doesn’t make either the fix or suggestions property of the lint result.allowInlineConfig - (optional) set to false to disable inline comments from changing ESLint rules.reportUnusedDisableDirectives - (optional) when set to true, adds reported errors for unused eslint-disable directives when no problems would be reported in the disabled area anyway.If the third argument is a string, it is interpreted as the filename.
You can call verify() like this:
const Linter = require("eslint").Linter;
const linter = new Linter();
const messages = linter.verify("var foo;", {
rules: {
semi: 2
}
}, { filename: "foo.js" });
// or using SourceCode
const Linter = require("eslint").Linter,
linter = new Linter(),
SourceCode = require("eslint").SourceCode;
const code = new SourceCode("var foo = bar;", ast);
const messages = linter.verify(code, {
rules: {
semi: 2
}
}, { filename: "foo.js" });
The verify() method returns an array of objects containing information about the linting warnings and errors. Here’s an example:
{
fatal: false,
ruleId: "semi",
severity: 2,
line: 1,
column: 23,
message: "Expected a semicolon.",
fix: {
range: [1, 15],
text: ";"
}
}
The information available for each linting message is:
column - the column on which the error occurred.fatal - usually omitted, but will be set to true if there’s a parsing error (not related to a rule).line - the line on which the error occurred.message - the message that should be output.nodeType - the node or token type that was reported with the problem.ruleId - the ID of the rule that triggered the messages (or null if fatal is true).severity - either 1 or 2, depending on your configuration.endColumn - the end column of the range on which the error occurred (this property is omitted if it’s not range).endLine - the end line of the range on which the error occurred (this property is omitted if it’s not range).fix - an object describing the fix for the problem (this property is omitted if no fix is available).suggestions - an array of objects describing possible lint fixes for editors to programmatically enable (see details in the Working with Rules docs).You can get the suppressed messages from the previous run by getSuppressedMessages() method. If there is not a previous run, getSuppressedMessage() will return an empty list.
const Linter = require("eslint").Linter;
const linter = new Linter();
const messages = linter.verify("var foo = bar; // eslint-disable-line -- Need to suppress", {
rules: {
semi: ["error", "never"]
}
}, { filename: "foo.js" });
const suppressedMessages = linter.getSuppressedMessages();
console.log(suppressedMessages[0].suppressions); // [{ "kind": "directive", "justification": "Need to suppress" }]
Linting message objects have a deprecated source property. This property will be removed from linting messages in an upcoming breaking release. If you depend on this property, you should now use the SourceCode instance provided by the linter.
You can also get an instance of the SourceCode object used inside of linter by using the getSourceCode() method:
const Linter = require("eslint").Linter;
const linter = new Linter();
const messages = linter.verify("var foo = bar;", {
rules: {
semi: 2
}
}, { filename: "foo.js" });
const code = linter.getSourceCode();
console.log(code.text); // "var foo = bar;"
In this way, you can retrieve the text and AST used for the last run of linter.verify().
This method is similar to verify except that it also runs autofixing logic, similar to the --fix flag on the command line. The result object will contain the autofixed code, along with any remaining linting messages for the code that were not autofixed.
const Linter = require("eslint").Linter;
const linter = new Linter();
const messages = linter.verifyAndFix("var foo", {
rules: {
semi: 2
}
});
Output object from this method:
{
fixed: true,
output: "var foo;",
messages: []
}
The information available is:
fixed - True, if the code was fixed.output - Fixed code text (might be the same as input if no fixes were applied).messages - Collection of all messages for the given code (It has the same information as explained above under verify block).Each Linter instance holds a map of rule names to loaded rule objects. By default, all ESLint core rules are loaded. If you want to use Linter with custom rules, you should use the defineRule method to register your rules by ID.
const Linter = require("eslint").Linter;
const linter = new Linter();
linter.defineRule("my-custom-rule", {
// (an ESLint rule)
create(context) {
// ...
}
});
const results = linter.verify("// some source text", { rules: { "my-custom-rule": "error" } });
This is a convenience method similar to Linter#defineRule, except that it allows you to define many rules at once using an object.
const Linter = require("eslint").Linter;
const linter = new Linter();
linter.defineRules({
"my-custom-rule": { /* an ESLint rule */ create() {} },
"another-custom-rule": { /* an ESLint rule */ create() {} }
});
const results = linter.verify("// some source text", {
rules: {
"my-custom-rule": "error",
"another-custom-rule": "warn"
}
});
This method returns a map of all loaded rules.
const Linter = require("eslint").Linter;
const linter = new Linter();
linter.getRules();
/*
Map {
'accessor-pairs' => { meta: { docs: [Object], schema: [Array] }, create: [Function: create] },
'array-bracket-newline' => { meta: { docs: [Object], schema: [Array] }, create: [Function: create] },
...
}
*/
Each instance of Linter holds a map of custom parsers. If you want to define a parser programmatically, you can add this function with the name of the parser as first argument and the parser object as second argument. The default "espree" parser will already be loaded for every Linter instance.
const Linter = require("eslint").Linter;
const linter = new Linter();
linter.defineParser("my-custom-parser", {
parse(code, options) {
// ...
}
});
const results = linter.verify("// some source text", { parser: "my-custom-parser" });
Each instance of Linter has a version property containing the semantic version number of ESLint that the Linter instance is from.
const Linter = require("eslint").Linter;
const linter = new Linter();
linter.version; // => '4.5.0'
There is also a Linter.version property that you can read without instantiating Linter:
const Linter = require("eslint").Linter;
Linter.version; // => '4.5.0'
eslint.RuleTester is a utility to write tests for ESLint rules. It is used internally for the bundled rules that come with ESLint, and it can also be used by plugins.
Example usage:
"use strict";
const rule = require("../../../lib/rules/my-rule"),
RuleTester = require("eslint").RuleTester;
const ruleTester = new RuleTester();
ruleTester.run("my-rule", rule, {
valid: [
{
code: "var foo = true",
options: [{ allowFoo: true }]
}
],
invalid: [
{
code: "var invalidVariable = true",
errors: [{ message: "Unexpected invalid variable." }]
},
{
code: "var invalidVariable = true",
errors: [{ message: /^Unexpected.+variable/ }]
}
]
});
The RuleTester constructor accepts an optional object argument, which can be used to specify defaults for your test cases. For example, if all of your test cases use ES2015, you can set it as a default:
const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 2015 } });
The RuleTester#run() method is used to run the tests. It should be passed the following arguments:
valid and invalid properties, each of which is an array containing test cases.A test case is an object with the following properties:
name (string, optional): The name to use for the test case, to make it easier to findcode (string, required): The source code that the rule should be run onoptions (array, optional): The options passed to the rule. The rule severity should not be included in this list.filename (string, optional): The filename for the given case (useful for rules that make assertions about filenames).only (boolean, optional): Run this case exclusively for debugging in supported test frameworks.In addition to the properties above, invalid test cases can also have the following properties:
errors (number or array, required): Asserts some properties of the errors that the rule is expected to produce when run on this code. If this is a number, asserts the number of errors produced. Otherwise, this should be a list of objects, each containing information about a single reported error. The following properties can be used for an error (all are optional):
message (string/regexp): The message for the errormessageId (string): The Id for the error. See testing errors with messageId for detailsdata (object): Placeholder data which can be used in combination with messageId
type (string): The type of the reported AST nodeline (number): The 1-based line number of the reported locationcolumn (number): The 1-based column number of the reported locationendLine (number): The 1-based line number of the end of the reported locationendColumn (number): The 1-based column number of the end of the reported locationsuggestions (array): An array of objects with suggestion details to check. See Testing Suggestions for detailsIf a string is provided as an error instead of an object, the string is used to assert the message of the error.
output (string, required if the rule fixes code): Asserts the output that will be produced when using this rule for a single pass of autofixing (e.g. with the --fix command line flag). If this is null, asserts that none of the reported problems suggest autofixes.
Any additional properties of a test case will be passed directly to the linter as config options. For example, a test case can have a parserOptions property to configure parser behavior:
{
code: "let foo;",
parserOptions: { ecmaVersion: 2015 }
}
If a valid test case only uses the code property, it can optionally be provided as a string containing the code, rather than an object with a code key.
messageId
If the rule under test uses messageIds, you can use messageId property in a test case to assert reported error’s messageId instead of its message.
{
code: "let foo;",
errors: [{ messageId: "unexpected" }]
}
For messages with placeholders, a test case can also use data property to additionally assert reported error’s message.
{
code: "let foo;",
errors: [{ messageId: "unexpected", data: { name: "foo" } }]
}
Please note that data in a test case does not assert data passed to context.report. Instead, it is used to form the expected message text which is then compared with the received message.
Suggestions can be tested by defining a suggestions key on an errors object. The options to check for the suggestions are the following (all are optional):
desc (string): The suggestion desc valuemessageId (string): The suggestion messageId value for suggestions that use messageIdsdata (object): Placeholder data which can be used in combination with messageId
output (string): A code string representing the result of applying the suggestion fix to the input codeExample:
ruleTester.run("my-rule-for-no-foo", rule, {
valid: [],
invalid: [{
code: "var foo;",
errors: [{
suggestions: [{
desc: "Rename identifier 'foo' to 'bar'",
output: "var bar;"
}]
}]
}]
})
messageId and data properties in suggestion test objects work the same way as in error test objects. See testing errors with messageId for details.
ruleTester.run("my-rule-for-no-foo", rule, {
valid: [],
invalid: [{
code: "var foo;",
errors: [{
suggestions: [{
messageId: "renameFoo",
data: { newName: "bar" },
output: "var bar;"
}]
}]
}]
})
RuleTester depends on two functions to run tests: describe and it. These functions can come from various places:
If RuleTester.describe and RuleTester.it have been set to function values, RuleTester will use RuleTester.describe and RuleTester.it to run tests. You can use this to customize the behavior of RuleTester to match a test framework that you’re using.
If RuleTester.itOnly has been set to a function value, RuleTester will call RuleTester.itOnly instead of RuleTester.it to run cases with only: true. If RuleTester.itOnly is not set but RuleTester.it has an only function property, RuleTester will fall back to RuleTester.it.only.
Otherwise, if describe and it are present as globals, RuleTester will use global.describe and global.it to run tests and global.it.only to run cases with only: true. This allows RuleTester to work when using frameworks like Mocha without any additional configuration.
Otherwise, RuleTester#run will simply execute all of the tests in sequence, and will throw an error if one of them fails. This means you can simply execute a test file that calls RuleTester.run using Node.js, without needing a testing framework.
RuleTester#run calls the describe function with two arguments: a string describing the rule, and a callback function. The callback calls the it function with a string describing the test case, and a test function. The test function will return successfully if the test passes, and throw an error if the test fails. The signature for only is the same as it. RuleTester calls either it or only for every case even when some cases have only: true, and the test framework is responsible for implementing test case exclusivity. (Note that this is the standard behavior for test suites when using frameworks like Mocha; this information is only relevant if you plan to customize RuleTester.describe, RuleTester.it, or RuleTester.itOnly.)
Example of customizing RuleTester:
"use strict";
const RuleTester = require("eslint").RuleTester,
test = require("my-test-runner"),
myRule = require("../../../lib/rules/my-rule");
RuleTester.describe = function(text, method) {
RuleTester.it.title = text;
return method.call(this);
};
RuleTester.it = function(text, method) {
test(RuleTester.it.title + ": " + text, method);
};
// then use RuleTester as documented
const ruleTester = new RuleTester();
ruleTester.run("my-rule", myRule, {
valid: [
// valid test cases
],
invalid: [
// invalid test cases
]
})
© OpenJS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/latest/developer-guide/nodejs-api