Drop kleur dependency in favor of node:util's styleText

package.json

@@ -23,8 +23,7 @@
   "dependencies": {
     "@matt.kantor/either": "^1.2.0",
     "@matt.kantor/option": "^1.0.0",
-    "@matt.kantor/parsing": "^2.0.0",
-    "kleur": "^4.1.5"
+    "@matt.kantor/parsing": "^2.0.0"
   },
   "engines": {
     "node": ">=22.18"

src/language/cli/output.ts

@@ -1,5 +1,4 @@
 import either, { type Either } from '@matt.kantor/either'
-import kleur from 'kleur'
 import { parseArgs } from 'node:util'
 import { type SyntaxTree } from '../parsing/syntax-tree.js'
 import {
@@ -27,7 +26,10 @@ export const handleOutput = async (
   if (typeof noColorArg !== 'boolean') {
     throw new Error('Unsupported value for --no-color')
   } else if (noColorArg === true) {
-    kleur.enabled = false
+    // Warning: the global state mutation here means that we can't style text in static contexts!
+    // Functions like `node:util`'s `styleText` shouldn't be called from the top level of modules.
+    delete process.env['FORCE_COLOR']
+    process.env['NO_COLOR'] = 'true'
   }
 
   const outputFormatArg = args.values['output-format']

src/language/unparsing/inline-plz.ts

@@ -1,5 +1,5 @@
 import either from '@matt.kantor/either'
-import kleur from 'kleur'
+import { styleText } from 'node:util'
 import type { Atom, Molecule } from '../parsing.js'
 import {
   moleculeAsKeyValuePairStrings,
@@ -9,7 +9,7 @@ import {
 import { punctuation, type Notation } from './unparsing-utilities.js'
 
 const unparseSugarFreeMolecule = (value: Molecule) => {
-  const { comma, closeBrace, openBrace } = punctuation(kleur)
+  const { comma, closeBrace, openBrace } = punctuation(styleText)
   if (Object.keys(value).length === 0) {
     return either.makeRight(openBrace + closeBrace)
   } else {

src/language/unparsing/plz-utilities.ts

@@ -1,6 +1,6 @@
 import either, { type Either, type Right } from '@matt.kantor/either'
 import parsing from '@matt.kantor/parsing'
-import kleur from 'kleur'
+import { styleText } from 'node:util'
 import type { UnserializableValueError } from '../errors.js'
 import type { Atom, Molecule } from '../parsing.js'
 import { unquotedAtomParser } from '../parsing/atom.js'
@@ -76,7 +76,7 @@ export const moleculeAsKeyValuePairStrings = (
   unparseAtomOrMolecule: UnparseAtomOrMolecule,
   options: { readonly ordinalKeys: 'omit' | 'preserve' },
 ): Either<UnserializableValueError, readonly string[]> => {
-  const { colon } = punctuation(kleur)
+  const { colon } = punctuation(styleText)
   const entries = Object.entries(value)
 
   const keyValuePairsAsStrings: string[] = []
@@ -96,8 +96,7 @@ export const moleculeAsKeyValuePairStrings = (
       ordinalPropertyKeyCounter += 1n
     } else {
       keyValuePairsAsStrings.push(
-        kleur
-          .cyan(quoteAtomIfNecessary(propertyKey).concat(colon))
+        styleText('cyan', quoteAtomIfNecessary(propertyKey).concat(colon))
           .concat(' ')
           .concat(valueAsStringResult.value),
       )
@@ -109,15 +108,15 @@ export const moleculeAsKeyValuePairStrings = (
 export const unparseAtom = (atom: string): Right<string> =>
   either.makeRight(
     /^@[^@]/.test(atom)
-      ? kleur.bold(kleur.underline(quoteAtomIfNecessary(atom)))
+      ? styleText(['bold', 'underline'], quoteAtomIfNecessary(atom))
       : quoteAtomIfNecessary(atom),
   )
 
 const requiresQuotation = (atom: string): boolean =>
   either.isLeft(parsing.parse(unquotedAtomParser, atom))
 
 const quoteAtomIfNecessary = (value: string): string => {
-  const { quote } = punctuation(kleur)
+  const { quote } = punctuation(styleText)
   if (requiresQuotation(value)) {
     return quote.concat(escapeStringContents(value)).concat(quote)
   } else {
@@ -126,7 +125,7 @@ const quoteAtomIfNecessary = (value: string): string => {
 }
 
 const quoteKeyPathComponentIfNecessary = (value: string): string => {
-  const { quote } = punctuation(kleur)
+  const { quote } = punctuation(styleText)
   const unquotedAtomResult = parsing.parse(unquotedAtomParser, value)
   if (either.isLeft(unquotedAtomResult) || value.includes('.')) {
     return quote.concat(escapeStringContents(value)).concat(quote)
@@ -153,7 +152,7 @@ const unparseSugaredApply = (
   expression: ApplyExpression,
   unparseAtomOrMolecule: UnparseAtomOrMolecule,
 ) => {
-  const { closeParenthesis, openParenthesis } = punctuation(kleur)
+  const { closeParenthesis, openParenthesis } = punctuation(styleText)
   return either.flatMap(
     either.map(
       either.flatMap(
@@ -188,8 +187,8 @@ const unparseSugaredFunction = (
   either.flatMap(serializeIfNeeded(expression[1].body), serializedBody =>
     either.map(unparseAtomOrMolecule(serializedBody), bodyAsString =>
       [
-        kleur.cyan(expression[1].parameter),
-        punctuation(kleur).arrow,
+        styleText('cyan', expression[1].parameter),
+        punctuation(styleText).arrow,
         bodyAsString,
       ].join(' '),
     ),
@@ -238,7 +237,7 @@ const unparseSugaredIndex = (
           message: 'invalid key path',
         })
       } else {
-        const { dot } = punctuation(kleur)
+        const { dot } = punctuation(styleText)
         return either.makeRight(
           unparsedObject
             .concat(dot)
@@ -254,8 +253,9 @@ const unparseSugaredLookup = (
   _unparseAtomOrMolecule: UnparseAtomOrMolecule,
 ) =>
   either.makeRight(
-    kleur.cyan(
-      punctuation(kleur).colon.concat(
+    styleText(
+      'cyan',
+      punctuation(styleText).colon.concat(
         quoteKeyPathComponentIfNecessary(expression[1].key),
       ),
     ),
@@ -280,7 +280,7 @@ const unparseSugaredGeneralizedKeywordExpression = (
         'expression cannot be faithfully represented using generalized keyword expression sugar',
     })
   } else {
-    const unparsedKeyword = kleur.bold(kleur.underline(expression['0']))
+    const unparsedKeyword = styleText(['bold', 'underline'], expression['0'])
     if ('1' in expression) {
       return either.map(
         either.flatMap(

src/language/unparsing/pretty-json.ts

@@ -1,31 +1,33 @@
 import type { Right } from '@matt.kantor/either'
 import either from '@matt.kantor/either'
-import kleur from 'kleur'
+import { styleText } from 'node:util'
 import type { Atom, Molecule } from '../parsing.js'
 import { indent, punctuation, type Notation } from './unparsing-utilities.js'
 
 const escapeStringContents = (value: string) =>
   value.replace('\\', '\\\\').replace('"', '\\"')
 
 const key = (value: Atom): string => {
-  const { quote } = punctuation(kleur)
-  return quote.concat(kleur.bold(escapeStringContents(value))).concat(quote)
+  const { quote } = punctuation(styleText)
+  return quote
+    .concat(styleText('bold', escapeStringContents(value)))
+    .concat(quote)
 }
 
 const unparseAtom = (value: Atom): Right<string> => {
-  const { quote } = punctuation(kleur)
+  const { quote } = punctuation(styleText)
   return either.makeRight(
     quote.concat(
       escapeStringContents(
-        /^@[^@]/.test(value) ? kleur.bold(kleur.underline(value)) : value,
+        /^@[^@]/.test(value) ? styleText(['bold', 'underline'], value) : value,
       ),
       quote,
     ),
   )
 }
 
 const unparseMolecule = (value: Molecule): Right<string> => {
-  const { closeBrace, colon, comma, openBrace } = punctuation(kleur)
+  const { closeBrace, colon, comma, openBrace } = punctuation(styleText)
   const entries = Object.entries(value)
   if (entries.length === 0) {
     return either.makeRight(openBrace.concat(closeBrace))

src/language/unparsing/pretty-plz.ts

@@ -1,5 +1,5 @@
 import either from '@matt.kantor/either'
-import kleur from 'kleur'
+import { styleText } from 'node:util'
 import type { Atom, Molecule } from '../parsing.js'
 import {
   moleculeAsKeyValuePairStrings,
@@ -9,7 +9,7 @@ import {
 import { indent, punctuation, type Notation } from './unparsing-utilities.js'
 
 const unparseSugarFreeMolecule = (value: Molecule) => {
-  const { closeBrace, openBrace } = punctuation(kleur)
+  const { closeBrace, openBrace } = punctuation(styleText)
   if (Object.keys(value).length === 0) {
     return either.makeRight(openBrace + closeBrace)
   } else {

src/language/unparsing/sugar-free-pretty-plz.ts

@@ -1,11 +1,11 @@
 import either from '@matt.kantor/either'
-import kleur from 'kleur'
+import { styleText } from 'node:util'
 import type { Atom, Molecule } from '../parsing.js'
 import { moleculeAsKeyValuePairStrings, unparseAtom } from './plz-utilities.js'
 import { indent, punctuation, type Notation } from './unparsing-utilities.js'
 
 const unparseMolecule = (value: Molecule) => {
-  const { closeBrace, openBrace } = punctuation(kleur)
+  const { closeBrace, openBrace } = punctuation(styleText)
   if (Object.keys(value).length === 0) {
     return either.makeRight(openBrace + closeBrace)
   } else {

src/language/unparsing/unparsing-utilities.ts

@@ -1,5 +1,5 @@
 import { type Either } from '@matt.kantor/either'
-import type { Kleur } from 'kleur'
+import * as util from 'node:util'
 import type { UnserializableValueError } from '../errors.js'
 import type { Atom, Molecule } from '../parsing.js'
 
@@ -18,14 +18,16 @@ export const indent = (spaces: number, textToIndent: string) => {
     .replace(/(\r?\n)/g, `$1${indentation}`)
 }
 
-export const punctuation = (kleur: Kleur) => ({
-  dot: kleur.dim('.'),
-  quote: kleur.dim('"'),
-  colon: kleur.dim(':'),
-  comma: kleur.dim(','),
-  openBrace: kleur.dim('{'),
-  closeBrace: kleur.dim('}'),
-  openParenthesis: kleur.dim('('),
-  closeParenthesis: kleur.dim(')'),
-  arrow: kleur.dim('=>'),
+// Note that `node:util`'s `styleText` changes behavior based on the current global state of
+// `process.env`, which may be mutated at runtime (e.g. to handle `--no-color`).
+export const punctuation = (styleText: typeof util.styleText) => ({
+  dot: styleText('dim', '.'),
+  quote: styleText('dim', '"'),
+  colon: styleText('dim', ':'),
+  comma: styleText('dim', ','),
+  openBrace: styleText('dim', '{'),
+  closeBrace: styleText('dim', '}'),
+  openParenthesis: styleText('dim', '('),
+  closeParenthesis: styleText('dim', ')'),
+  arrow: styleText('dim', '=>'),
 })