Clean up helpers which are always present in ES2020 (microsoft#55515)

Author: jakebailey

src/compiler/commandLineParser.ts

@@ -110,7 +110,6 @@ import {
     toFileNameLowerCase,
     toPath,
     tracing,
-    trimString,
     TsConfigOnlyOption,
     TsConfigSourceFile,
     TypeAcquisition,
@@ -1699,13 +1698,13 @@ function createDiagnosticForInvalidCustomType(opt: CommandLineOptionOfCustomType
 }
 
 /** @internal */
-export function parseCustomTypeOption(opt: CommandLineOptionOfCustomType, value: string, errors: Diagnostic[]) {
-    return convertJsonOptionOfCustomType(opt, trimString(value || ""), errors);
+export function parseCustomTypeOption(opt: CommandLineOptionOfCustomType, value: string | undefined, errors: Diagnostic[]) {
+    return convertJsonOptionOfCustomType(opt, (value ?? "").trim(), errors);
 }
 
 /** @internal */
 export function parseListTypeOption(opt: CommandLineOptionOfListType, value = "", errors: Diagnostic[]): string | (string | number)[] | undefined {
-    value = trimString(value);
+    value = value.trim();
     if (startsWith(value, "-")) {
         return undefined;
     }

src/compiler/core.ts

@@ -5,7 +5,6 @@ import {
     Comparison,
     Debug,
     EqualityComparer,
-    isWhiteSpaceLike,
     MapLike,
     Queue,
     SortedArray,
@@ -2241,11 +2240,7 @@ export function getStringComparer(ignoreCase?: boolean) {
  * Creates a string comparer for use with string collation in the UI.
  */
 const createUIStringComparer = (() => {
-    let defaultComparer: Comparer<string> | undefined;
-    let enUSComparer: Comparer<string> | undefined;
-
-    const stringComparerFactory = getStringComparerFactory();
-    return createStringComparer;
+    return createIntlCollatorStringComparer;
 
     function compareWithCallback(a: string | undefined, b: string | undefined, comparer: (a: string, b: string) => number) {
         if (a === b) return Comparison.EqualTo;
@@ -2261,70 +2256,6 @@ const createUIStringComparer = (() => {
         const comparer = new Intl.Collator(locale, { usage: "sort", sensitivity: "variant" }).compare;
         return (a, b) => compareWithCallback(a, b, comparer);
     }
-
-    function createLocaleCompareStringComparer(locale: string | undefined): Comparer<string> {
-        // if the locale is not the default locale (`undefined`), use the fallback comparer.
-        if (locale !== undefined) return createFallbackStringComparer();
-
-        return (a, b) => compareWithCallback(a, b, compareStrings);
-
-        function compareStrings(a: string, b: string) {
-            return a.localeCompare(b);
-        }
-    }
-
-    function createFallbackStringComparer(): Comparer<string> {
-        // An ordinal comparison puts "A" after "b", but for the UI we want "A" before "b".
-        // We first sort case insensitively.  So "Aaa" will come before "baa".
-        // Then we sort case sensitively, so "aaa" will come before "Aaa".
-        //
-        // For case insensitive comparisons we always map both strings to their
-        // upper-case form as some unicode characters do not properly round-trip to
-        // lowercase (such as `ẞ` (German sharp capital s)).
-        return (a, b) => compareWithCallback(a, b, compareDictionaryOrder);
-
-        function compareDictionaryOrder(a: string, b: string) {
-            return compareStrings(a.toUpperCase(), b.toUpperCase()) || compareStrings(a, b);
-        }
-
-        function compareStrings(a: string, b: string) {
-            return a < b ? Comparison.LessThan : a > b ? Comparison.GreaterThan : Comparison.EqualTo;
-        }
-    }
-
-    function getStringComparerFactory() {
-        // If the host supports Intl, we use it for comparisons using the default locale.
-        if (typeof Intl === "object" && typeof Intl.Collator === "function") {
-            return createIntlCollatorStringComparer;
-        }
-
-        // If the host does not support Intl, we fall back to localeCompare.
-        // localeCompare in Node v0.10 is just an ordinal comparison, so don't use it.
-        if (
-            typeof String.prototype.localeCompare === "function" &&
-            typeof String.prototype.toLocaleUpperCase === "function" &&
-            "a".localeCompare("B") < 0
-        ) {
-            return createLocaleCompareStringComparer;
-        }
-
-        // Otherwise, fall back to ordinal comparison:
-        return createFallbackStringComparer;
-    }
-
-    function createStringComparer(locale: string | undefined) {
-        // Hold onto common string comparers. This avoids constantly reallocating comparers during
-        // tests.
-        if (locale === undefined) {
-            return defaultComparer || (defaultComparer = stringComparerFactory(locale));
-        }
-        else if (locale === "en-US") {
-            return enUSComparer || (enUSComparer = stringComparerFactory(locale));
-        }
-        else {
-            return stringComparerFactory(locale);
-        }
-    }
 })();
 
 let uiComparerCaseSensitive: Comparer<string> | undefined;
@@ -2772,32 +2703,6 @@ function cartesianProductWorker<T>(arrays: readonly (readonly T[])[], result: (r
     }
 }
 
-/**
- * Returns string left-padded with spaces or zeros until it reaches the given length.
- *
- * @param s String to pad.
- * @param length Final padded length. If less than or equal to 's.length', returns 's' unchanged.
- * @param padString Character to use as padding (default " ").
- *
- * @internal
- */
-export function padLeft(s: string, length: number, padString: " " | "0" = " ") {
-    return length <= s.length ? s : padString.repeat(length - s.length) + s;
-}
-
-/**
- * Returns string right-padded with spaces until it reaches the given length.
- *
- * @param s String to pad.
- * @param length Final padded length. If less than or equal to 's.length', returns 's' unchanged.
- * @param padString Character to use as padding (default " ").
- *
- * @internal
- */
-export function padRight(s: string, length: number, padString: " " = " ") {
-    return length <= s.length ? s : s + padString.repeat(length - s.length);
-}
-
 /** @internal */
 export function takeWhile<T, U extends T>(array: readonly T[], predicate: (element: T) => element is U): U[];
 /** @internal */
@@ -2829,42 +2734,6 @@ export function skipWhile<T, U extends T>(array: readonly T[] | undefined, predi
     }
 }
 
-/**
- * Removes the leading and trailing white space and line terminator characters from a string.
- *
- * @internal
- */
-export const trimString = !!String.prototype.trim ? ((s: string) => s.trim()) : (s: string) => trimStringEnd(trimStringStart(s));
-
-/**
- * Returns a copy with trailing whitespace removed.
- *
- * @internal
- */
-export const trimStringEnd = !!String.prototype.trimEnd ? ((s: string) => s.trimEnd()) : trimEndImpl;
-
-/**
- * Returns a copy with leading whitespace removed.
- *
- * @internal
- */
-export const trimStringStart = !!String.prototype.trimStart ? ((s: string) => s.trimStart()) : (s: string) => s.replace(/^\s+/g, "");
-
-/**
- * https://jsbench.me/gjkoxld4au/1
- * The simple regex for this, /\s+$/g is O(n^2) in v8.
- * The native .trimEnd method is by far best, but since that's technically ES2019,
- * we provide a (still much faster than the simple regex) fallback.
- */
-function trimEndImpl(s: string) {
-    let end = s.length - 1;
-    while (end >= 0) {
-        if (!isWhiteSpaceLike(s.charCodeAt(end))) break;
-        end--;
-    }
-    return s.slice(0, end + 1);
-}
-
 /** @internal */
 export function isNodeLikeSystem(): boolean {
     // This is defined here rather than in sys.ts to prevent a cycle from its

src/compiler/parser.ts

@@ -368,8 +368,6 @@ import {
     tokenToString,
     tracing,
     TransformFlags,
-    trimString,
-    trimStringEnd,
     TryStatement,
     TupleTypeNode,
     TypeAliasDeclaration,
@@ -8895,7 +8893,7 @@ namespace Parser {
                         nextTokenJSDoc();
                     }
                 }
-                const trimmedComments = trimStringEnd(comments.join(""));
+                const trimmedComments = comments.join("").trimEnd();
                 if (parts.length && trimmedComments.length) {
                     parts.push(finishNode(factory.createJSDocText(trimmedComments), linkEnd ?? start, commentsPos));
                 }
@@ -8912,7 +8910,7 @@ namespace Parser {
 
             function removeTrailingWhitespace(comments: string[]) {
                 while (comments.length) {
-                    const trimmed = trimStringEnd(comments[comments.length - 1]);
+                    const trimmed = comments[comments.length - 1].trimEnd();
                     if (trimmed === "") {
                         comments.pop();
                     }
@@ -9174,7 +9172,7 @@ namespace Parser {
                 }
 
                 removeLeadingNewlines(comments);
-                const trimmedComments = trimStringEnd(comments.join(""));
+                const trimmedComments = comments.join("").trimEnd();
                 if (parts.length) {
                     if (trimmedComments.length) {
                         parts.push(finishNode(factory.createJSDocText(trimmedComments), linkEnd ?? commentsPos));
@@ -10618,7 +10616,7 @@ function addPragmaForMatch(pragmas: PragmaPseudoMapEntry[], range: CommentRange,
 function getNamedPragmaArguments(pragma: PragmaDefinition, text: string | undefined): { [index: string]: string; } | "fail" {
     if (!text) return {};
     if (!pragma.args) return {};
-    const args = trimString(text).split(/\s+/);
+    const args = text.trim().split(/\s+/);
     const argMap: { [index: string]: string; } = {};
     for (let i = 0; i < pragma.args.length; i++) {
         const argument = pragma.args[i];

src/compiler/program.ts

@@ -250,7 +250,6 @@ import {
     packageIdToPackageName,
     packageIdToString,
     PackageJsonInfoCache,
-    padLeft,
     ParameterDeclaration,
     ParseConfigFileHost,
     ParsedCommandLine,
@@ -318,7 +317,6 @@ import {
     toPath as ts_toPath,
     trace,
     tracing,
-    trimStringEnd,
     TsConfigSourceFile,
     TypeChecker,
     typeDirectiveIsEqualTo,
@@ -722,22 +720,22 @@ function formatCodeSpan(file: SourceFile, start: number, length: number, indent:
         // If the error spans over 5 lines, we'll only show the first 2 and last 2 lines,
         // so we'll skip ahead to the second-to-last line.
         if (hasMoreThanFiveLines && firstLine + 1 < i && i < lastLine - 1) {
-            context += indent + formatColorAndReset(padLeft(ellipsis, gutterWidth), gutterStyleSequence) + gutterSeparator + host.getNewLine();
+            context += indent + formatColorAndReset(ellipsis.padStart(gutterWidth), gutterStyleSequence) + gutterSeparator + host.getNewLine();
             i = lastLine - 1;
         }
 
         const lineStart = getPositionOfLineAndCharacter(file, i, 0);
         const lineEnd = i < lastLineInFile ? getPositionOfLineAndCharacter(file, i + 1, 0) : file.text.length;
         let lineContent = file.text.slice(lineStart, lineEnd);
-        lineContent = trimStringEnd(lineContent); // trim from end
+        lineContent = lineContent.trimEnd(); // trim from end
         lineContent = lineContent.replace(/\t/g, " "); // convert tabs to single spaces
 
         // Output the gutter and the actual contents of the line.
-        context += indent + formatColorAndReset(padLeft(i + 1 + "", gutterWidth), gutterStyleSequence) + gutterSeparator;
+        context += indent + formatColorAndReset((i + 1 + "").padStart(gutterWidth), gutterStyleSequence) + gutterSeparator;
         context += lineContent + host.getNewLine();
 
         // Output the gutter and the error span for the line using tildes.
-        context += indent + formatColorAndReset(padLeft("", gutterWidth), gutterStyleSequence) + gutterSeparator;
+        context += indent + formatColorAndReset("".padStart(gutterWidth), gutterStyleSequence) + gutterSeparator;
         context += squiggleColor;
         if (i === firstLine) {
             // If we're on the last line, then limit it to the last character of the last line.

src/compiler/scanner.ts

@@ -18,15 +18,13 @@ import {
     LanguageVariant,
     LineAndCharacter,
     MapLike,
-    padLeft,
     parsePseudoBigInt,
     positionIsSynthesized,
     PunctuationOrKeywordSyntaxKind,
     ScriptTarget,
     SourceFileLike,
     SyntaxKind,
     TokenFlags,
-    trimStringStart,
 } from "./_namespaces/ts";
 
 export type ErrorCallback = (message: DiagnosticMessage, length: number, arg0?: any) => void;
@@ -1490,7 +1488,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                 tokenFlags |= TokenFlags.ContainsInvalidEscape;
                 if (shouldEmitInvalidEscapeError) {
                     const code = parseInt(text.substring(start + 1, pos), 8);
-                    error(Diagnostics.Octal_escape_sequences_are_not_allowed_Use_the_syntax_0, start, pos - start, "\\x" + padLeft(code.toString(16), 2, "0"));
+                    error(Diagnostics.Octal_escape_sequences_are_not_allowed_Use_the_syntax_0, start, pos - start, "\\x" + code.toString(16).padStart(2, "0"));
                     return String.fromCharCode(code);
                 }
                 return text.substring(start, pos);
@@ -2392,7 +2390,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
         commentDirectiveRegEx: RegExp,
         lineStart: number,
     ) {
-        const type = getDirectiveFromComment(trimStringStart(text), commentDirectiveRegEx);
+        const type = getDirectiveFromComment(text.trimStart(), commentDirectiveRegEx);
         if (type === undefined) {
             return commentDirectives;
         }
@@ -2793,25 +2791,10 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
 }
 
 /** @internal */
-const codePointAt: (s: string, i: number) => number = (String.prototype as any).codePointAt ? (s, i) => (s as any).codePointAt(i) : function codePointAt(str, i): number {
-    // from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt
-    const size = str.length;
-    // Account for out-of-bounds indices:
-    if (i < 0 || i >= size) {
-        return undefined!; // String.codePointAt returns `undefined` for OOB indexes
-    }
-    // Get the first code unit
-    const first = str.charCodeAt(i);
-    // check if it's the start of a surrogate pair
-    if (first >= 0xD800 && first <= 0xDBFF && size > i + 1) { // high surrogate and there is a next code unit
-        const second = str.charCodeAt(i + 1);
-        if (second >= 0xDC00 && second <= 0xDFFF) { // low surrogate
-            // https://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
-            return (first - 0xD800) * 0x400 + second - 0xDC00 + 0x10000;
-        }
-    }
-    return first;
-};
+function codePointAt(s: string, i: number): number {
+    // TODO(jakebailey): this is wrong and should have ?? 0; but all users are okay with it
+    return s.codePointAt(i)!;
+}
 
 /** @internal */
 function charSize(ch: number) {

src/compiler/semver.ts

@@ -8,7 +8,6 @@ import {
     isArray,
     map,
     some,
-    trimString,
 } from "./_namespaces/ts";
 
 // https://semver.org/#spec-item-2
@@ -275,17 +274,17 @@ const rangeRegExp = /^(~|\^|<|<=|>|>=|=)?\s*([a-z0-9-+.*]+)$/i;
 
 function parseRange(text: string) {
     const alternatives: Comparator[][] = [];
-    for (let range of trimString(text).split(logicalOrRegExp)) {
+    for (let range of text.trim().split(logicalOrRegExp)) {
         if (!range) continue;
         const comparators: Comparator[] = [];
-        range = trimString(range);
+        range = range.trim();
         const match = hyphenRegExp.exec(range);
         if (match) {
             if (!parseHyphen(match[1], match[2], comparators)) return undefined;
         }
         else {
             for (const simple of range.split(whitespaceRegExp)) {
-                const match = rangeRegExp.exec(trimString(simple));
+                const match = rangeRegExp.exec(simple.trim());
                 if (!match || !parseComparator(match[1], match[2], comparators)) return undefined;
             }
         }

src/compiler/sourcemap.ts

@@ -24,7 +24,6 @@ import {
     sortAndDeduplicate,
     SortedReadonlyArray,
     SourceMapGenerator,
-    trimStringEnd,
 } from "./_namespaces/ts";
 import * as performance from "./_namespaces/ts.performance";
 
@@ -392,7 +391,7 @@ export function tryGetSourceMappingURL(lineInfo: LineInfo) {
         const line = lineInfo.getLineText(index);
         const comment = sourceMapCommentRegExp.exec(line);
         if (comment) {
-            return trimStringEnd(comment[1]);
+            return comment[1].trimEnd();
         }
         // If we see a non-whitespace/map comment-like line, break, to avoid scanning up the entire file
         else if (!line.match(whitespaceOrMapCommentRegExp)) {