# Scope analysis utilities
# findVariable
const variable = utils.findVariable(initialScope, name)
Get the variable of a given name.
# Parameters
Name | Type | Description |
---|---|---|
initialScope | Scope | The scope object to start finding variables. |
name | string or Node | The variable name to find. This can be an Identifier node. |
# Return value
The found variable or null
.
# Example
const { findVariable } = require("eslint-utils")
module.exports = {
meta: {},
create(context) {
return {
Identifier(node) {
const variable = findVariable(context.getScope(), node)
},
}
},
}
# getInnermostScope
const scope = utils.getInnermostScope(initialScope, node)
Get the innermost scope which contains a given node.
# Parameters
Name | Type | Description |
---|---|---|
initialScope | Scope | The scope to start finding. |
node | Node | The node to find the innermost scope. |
# Return value
The innermost scope which contains the given node.
If such scope doesn't exist then it returns the 1st argument initialScope
.
# Example
const { getInnermostScope } = require("eslint-utils")
module.exports = {
meta: {},
create(context) {
return {
"Program"(node) {
const globalScope = context.getScope()
const maybeNodejsScope = getInnermostScope(globalScope, node)
},
}
},
}
# ReferenceTracker class
const tracker = new utils.ReferenceTracker(globalScope, options)
The tracker for references. This provides reference tracking for global variables, CommonJS modules, and ES modules.
# Parameters
Name | Type | Description |
---|---|---|
globalScope | Scope | The global scope. |
options.mode | "strict" or "legacy" | The mode which determines how the tracker.iterateEsmReferences() method scans CommonJS modules. If this is "strict" , the method binds CommonJS modules to the default export. Otherwise, the method binds CommonJS modules to both the default export and named exports. Optional. Default is "strict" . |
options.globalObjectNames | string[] | The name list of Global Object. Optional. Default is ["global", "self", "window"] . |
# tracker.iterateGlobalReferences
const it = tracker.iterateGlobalReferences(traceMap)
Iterate the references that the given traceMap
determined.
This method starts to search from global variables.
# Parameters
Name | Type | Description |
---|---|---|
traceMap | object | The object which determines global variables and properties it iterates. |
# Return value
The Iterator which iterates the reference of global variables. Every reference is the object that has the following properties.
Name | Type | Description |
---|---|---|
node | Node | The node of the reference. |
path | string[] | The path of the reference. For example, if it's the access of console.log then ["console", "log"] . |
type | symbol | The reference type. If this is ReferenceTracker.READ then it read the variable (or property). If this is ReferenceTracker.CALL then it called the variable (or property). If this is ReferenceTracker.CONSTRUCT then it called the variable (or property) with the new operator. |
entry | any | The property value of any of ReferenceTracker.READ , ReferenceTracker.CALL , and ReferenceTracker.CONSTRUCT . |
# Examples
const { ReferenceTracker } = require("eslint-utils")
module.exports = {
meta: {},
create(context) {
return {
"Program:exit"() {
const tracker = new ReferenceTracker(context.getScope())
const traceMap = {
// Find `console.log`, `console.info`, `console.warn`, and `console.error`.
console: {
log: { [ReferenceTracker.READ]: true },
info: { [ReferenceTracker.READ]: true },
warn: { [ReferenceTracker.READ]: true },
error: { [ReferenceTracker.READ]: true },
},
// Find `Buffer()` and `new Buffer()`.
Buffer: {
[ReferenceTracker.CALL]: true,
[ReferenceTracker.CONSTRUCT]: true,
},
}
for (const { node, path } of tracker.iterateGlobalReferences(traceMap)) {
context.report({
node,
message: "disallow {{name}}.",
data: { name: path.join(".") },
})
}
},
}
},
}
# tracker.iterateCjsReferences
const it = tracker.iterateCjsReferences(traceMap)
Iterate the references that the given traceMap
determined.
This method starts to search from require()
expression.
# Parameters
Name | Type | Description |
---|---|---|
traceMap | object | The object which determines modules it iterates. |
# Return value
The Iterator which iterates the reference of modules. Every reference is the object that has the following properties.
Name | Type | Description |
---|---|---|
node | Node | The node of the reference. |
path | string[] | The path of the reference. For example, if it's the access of fs.exists then ["fs", "exists"] . |
type | symbol | The reference type. If this is ReferenceTracker.READ then it read the variable (or property). If this is ReferenceTracker.CALL then it called the variable (or property). If this is ReferenceTracker.CONSTRUCT then it called the variable (or property) with the new operator. |
entry | any | The property value of any of ReferenceTracker.READ , ReferenceTracker.CALL , and ReferenceTracker.CONSTRUCT . |
# Examples
const { ReferenceTracker } = require("eslint-utils")
module.exports = {
meta: {},
create(context) {
return {
"Program:exit"() {
const tracker = new ReferenceTracker(context.getScope())
const traceMap = {
// Find `Buffer()` and `new Buffer()` of `buffer` module.
buffer: {
Buffer: {
[ReferenceTracker.CALL]: true,
[ReferenceTracker.CONSTRUCT]: true,
},
},
// Find `exists` of `fs` module.
fs: {
exists: {
[ReferenceTracker.READ]: true,
},
},
}
for (const { node, path } of tracker.iterateCjsReferences(traceMap)) {
context.report({
node,
message: "disallow {{name}}.",
data: { name: path.join(".") },
})
}
},
}
},
}
# tracker.iterateEsmReferences
const it = tracker.iterateEsmReferences(traceMap)
Iterate the references that the given traceMap
determined.
This method starts to search from import
/export
declarations.
# Parameters
Name | Type | Description |
---|---|---|
traceMap | object | The object which determines modules it iterates. |
# Return value
The Iterator which iterates the reference of modules. Every reference is the object that has the following properties.
Name | Type | Description |
---|---|---|
node | Node | The node of the reference. |
path | string[] | The path of the reference. For example, if it's the access of fs.exists then ["fs", "exists"] . |
type | symbol | The reference type. If this is ReferenceTracker.READ then it read the variable (or property). If this is ReferenceTracker.CALL then it called the variable (or property). If this is ReferenceTracker.CONSTRUCT then it called the variable (or property) with the new operator. |
entry | any | The property value of any of ReferenceTracker.READ , ReferenceTracker.CALL , and ReferenceTracker.CONSTRUCT . |
# Examples
const { ReferenceTracker } = require("eslint-utils")
module.exports = {
meta: {},
create(context) {
return {
"Program:exit"() {
const tracker = new ReferenceTracker(context.getScope())
const traceMap = {
// Find `Buffer()` and `new Buffer()` of `buffer` module.
buffer: {
Buffer: {
[ReferenceTracker.CALL]: true,
[ReferenceTracker.CONSTRUCT]: true,
},
},
// Find `exists` of `fs` module.
fs: {
exists: {
[ReferenceTracker.READ]: true,
},
},
}
for (const { node, path } of tracker.iterateEsmReferences(traceMap)) {
context.report({
node,
message: "disallow {{name}}.",
data: { name: path.join(".") },
})
}
},
}
},
}