Skip to content

Add support for v flag to regexp/no-useless-character-class rule #593

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
RunDevelopment merged 10 commits into from
Sep 21, 2023
+365 −55
Merged

Add support for v flag to regexp/no-useless-character-class rule #593

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
77967ae
Improve `regexp/no-useless-character-class` rule auto-fix to supports…
ota-meshi Sep 10, 2023
87dbcbc
Create gold-baboons-clap.md
ota-meshi Sep 10, 2023
6c3ab8e
Update gold-baboons-clap.md
ota-meshi Sep 10, 2023
4f29d51
Add support for v flag to regexp/no-useless-character-class rule
ota-meshi Sep 10, 2023
4737d41
add test cases
ota-meshi Sep 10, 2023
03a0c10
fix messages
ota-meshi Sep 10, 2023
3305503
add support for simple nesting character class
ota-meshi Sep 10, 2023
f63cfbe
fix: change message
ota-meshi Sep 10, 2023
db79472
Merge branch 'master' into no-useless-character-class
ota-meshi Sep 15, 2023
699695e
fix
ota-meshi Sep 15, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions .changeset/gold-baboons-clap.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
---
"eslint-plugin-regexp": minor
---

Add support for v flag to `regexp/no-useless-character-class` rule
297 changes: 243 additions & 54 deletions lib/rules/no-useless-character-class.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,23 @@
import type { RegExpVisitor } from "@eslint-community/regexpp/visitor"
import type { RegExpContext } from "../utils"
import { canUnwrapped, createRule, defineRegexpVisitor } from "../utils"
import type {
CharacterClass,
CharacterClassElement,
ExpressionCharacterClass,
UnicodeSetsCharacterClass,
} from "@eslint-community/regexpp/ast"

const ESCAPES_OUTSIDE_CHARACTER_CLASS = new Set("$()*+./?[{|")
const ESCAPES_OUTSIDE_CHARACTER_CLASS_WITH_U = new Set([
...ESCAPES_OUTSIDE_CHARACTER_CLASS,
"}",
])
// A single character set of ClassSetReservedDoublePunctuator.
// && !! ## $$ %% ** ++ ,, .. :: ;; << == >> ?? @@ ^^ `` ~~ are ClassSetReservedDoublePunctuator
const REGEX_CLASS_SET_RESERVED_DOUBLE_PUNCTUATOR = new Set(
"!#$%&*+,.:;<=>?@^`~",
)

export default createRule("no-useless-character-class", {
meta: {
Expand All @@ -27,8 +44,10 @@ export default createRule("no-useless-character-class", {
},
],
messages: {
unexpected:
unexpectedCharacterClassWith:
"Unexpected character class with one {{type}}. Can remove brackets{{additional}}.",
unexpectedUnnecessaryNestingCharacterClass:
"Unexpected unnecessary nesting character class. Can remove brackets.",
},
type: "suggestion", // "problem",
},
Expand All @@ -37,88 +56,258 @@ export default createRule("no-useless-character-class", {

function createVisitor({
node,
pattern,
flags,
fixReplaceNode,
getRegexpLocation,
}: RegExpContext): RegExpVisitor.Handlers {
const characterClassStack: (
| CharacterClass
| ExpressionCharacterClass
)[] = []
return {
onExpressionCharacterClassEnter(eccNode) {
characterClassStack.push(eccNode)
},
onExpressionCharacterClassLeave() {
characterClassStack.pop()
},
onCharacterClassEnter(ccNode) {
if (ccNode.elements.length !== 1) {
return
}
characterClassStack.push(ccNode)
},
onCharacterClassLeave(ccNode) {
characterClassStack.pop()
if (ccNode.negate) {
return
}
const element = ccNode.elements[0]
if (ignores.length > 0 && ignores.includes(element.raw)) {
return
}
if (element.type === "Character") {
if (element.raw === "\\b") {
// Backspace escape
return
let messageId: string,
messageData: { type: string; additional?: string }
const unwrapped: string[] = ccNode.elements.map(
(_e, index) => {
const element = ccNode.elements[index]
return (
(index === 0
? getEscapedFirstRawIfNeeded(element)
: null) ??
(index === ccNode.elements.length - 1
? getEscapedLastRawIfNeeded(element)
: null) ??
element.raw
)
},
)
if (
ccNode.elements.length !== 1 &&
ccNode.parent.type === "CharacterClass"
) {
messageId = "unexpectedUnnecessaryNestingCharacterClass"
messageData = {
type: "unnecessary nesting character class",
}
if (
/^\\\d+$/u.test(element.raw) &&
!element.raw.startsWith("\\0")
) {
// Avoid back reference
if (!ccNode.elements.length) {
// empty character class
const nextElement =
ccNode.parent.elements[
ccNode.parent.elements.indexOf(
ccNode as UnicodeSetsCharacterClass,
) + 1
]
if (
nextElement &&
isNeedEscapedForFirstElement(nextElement)
) {
unwrapped.push("\\") // Add a backslash to escape the next character.
}
}
} else {
if (ccNode.elements.length !== 1) {
return
}
const element = ccNode.elements[0]
if (
ignores.length > 0 &&
ignores.includes(
String.fromCodePoint(element.value),
)
ignores.includes(element.raw)
) {
return
}
if (!canUnwrapped(ccNode, element.raw)) {
return
}
} else if (element.type === "CharacterClassRange") {
if (element.min.value !== element.max.value) {
if (element.type === "Character") {
if (element.raw === "\\b") {
// Backspace escape
return
}
if (
/^\\\d+$/u.test(element.raw) &&
!element.raw.startsWith("\\0")
) {
// Avoid back reference
return
}
if (
ignores.length > 0 &&
ignores.includes(
String.fromCodePoint(element.value),
)
) {
return
}
if (!canUnwrapped(ccNode, element.raw)) {
return
}
messageData = { type: "character" }
} else if (element.type === "CharacterClassRange") {
if (element.min.value !== element.max.value) {
return
}
messageData = {
type: "character class range",
additional: " and range",
}
unwrapped[0] =
getEscapedFirstRawIfNeeded(element.min) ??
getEscapedLastRawIfNeeded(element.min) ??
element.min.raw
} else if (element.type === "ClassStringDisjunction") {
if (!characterClassStack.length) {
// Only nesting character class
return
}
messageData = { type: "string literal" }
} else if (element.type === "CharacterSet") {
messageData = { type: "character class escape" }
} else if (
element.type === "CharacterClass" ||
element.type === "ExpressionCharacterClass"
) {
messageData = { type: "character class" }
} else {
return
}
} else if (element.type !== "CharacterSet") {
return
messageId = "unexpectedCharacterClassWith"
}

context.report({
node,
loc: getRegexpLocation(ccNode),
messageId: "unexpected",
messageId,
data: {
type:
element.type === "Character"
? "character"
: element.type === "CharacterClassRange"
? "character class range"
: "character class escape",
additional:
element.type === "CharacterClassRange"
? " and range"
: "",
type: messageData.type,
additional: messageData.additional || "",
},
fix: fixReplaceNode(ccNode, () => {
let text: string =
element.type === "CharacterClassRange"
? element.min.raw
: element.raw
fix: fixReplaceNode(ccNode, unwrapped.join("")),
})

/**
* Checks whether an escape is required if the given element is placed first
* after character class replacement.
*/
function isNeedEscapedForFirstElement(
element: CharacterClassElement,
) {
const char =
element.type === "Character"
? element.raw
: element.type === "CharacterClassRange"
? element.min.raw
: null
if (char == null) {
return false
}
if (characterClassStack.length) {
// Nesting character class

// Avoid [A&&[&]] => [A&&&]
if (
element.type === "Character" ||
element.type === "CharacterClassRange"
REGEX_CLASS_SET_RESERVED_DOUBLE_PUNCTUATOR.has(
char,
) &&
// The previous character is the same
pattern[ccNode.start - 1] === char
) {
if (
/^[$()*+./?[{|]$/u.test(text) ||
(flags.unicode && text === "}")
) {
text = `\\${text}`
}
return true
}
return text
}),
})

// Avoid [[]^] => [^]
return (
char === "^" &&
ccNode.parent.type === "CharacterClass" &&
ccNode.parent.elements[0] === ccNode
)
}

// Flat character class
return (
flags.unicode
? ESCAPES_OUTSIDE_CHARACTER_CLASS_WITH_U
: ESCAPES_OUTSIDE_CHARACTER_CLASS
).has(char)
}

/**
* Checks whether an escape is required if the given element is placed last
* after character class replacement.
*/
function needEscapedForLastElement(
element: CharacterClassElement,
) {
const char =
element.type === "Character"
? element.raw
: element.type === "CharacterClassRange"
? element.max.raw
: null
if (char == null) {
return false
}
if (characterClassStack.length) {
// Nesting character class

// Avoid [A[&]&B] => [A&&B]
return (
REGEX_CLASS_SET_RESERVED_DOUBLE_PUNCTUATOR.has(
char,
) &&
// The next character is the same
pattern[ccNode.end] === char
)
}
return false
}

/**
* Returns the escaped raw text, if the given first element requires escaping.
* Otherwise, returns null.
*/
function getEscapedFirstRawIfNeeded(
firstElement: CharacterClassElement,
) {
if (isNeedEscapedForFirstElement(firstElement)) {
return `\\${firstElement.raw}`
}
return null
}

/**
* Returns the escaped raw text, if the given last element requires escaping.
* Otherwise, returns null.
*/
function getEscapedLastRawIfNeeded(
lastElement: CharacterClassElement,
) {
if (needEscapedForLastElement(lastElement)) {
const lastRaw =
lastElement.type === "Character"
? lastElement.raw
: lastElement.type === "CharacterClassRange"
? lastElement.max.raw
: "" // never
const prefix = lastElement.raw.slice(
0,
-lastRaw.length,
)
return `${prefix}\\${lastRaw}`
}
return null
}
},
}
}
Expand Down
Loading