Handle omitted and primitive string search values in static calls

packages/compiler/src/frontend/lowering/containers/string-and-regexp.ts

@@ -6,7 +6,7 @@ import type { Lowerer } from "../lowerer.js";
 import { own } from "../lowerer.js";
 import { isRequireMainFilename } from "../expressions/optional-chains.js";
 import { STR_METHODS } from "../surfaces.js";
-import { defaultAfterUndefined, lowerOptionalArgument, lowerPositionArgument, lowerStaticallyUndefinedArgument, positionNumber } from "../optional-arguments.js";
+import { defaultAfterUndefined, lowerOptionalArgument, lowerPositionArgument, lowerStaticallyUndefinedArgument, lowerStringSearchArgument, positionNumber } from "../optional-arguments.js";
 
 function lowerSplitLimitArg(lowerer: Lowerer, node: ts.Expression | undefined, loc: SrcLoc): IrExpr {
   const defaultValue: IrExpr = { kind: "numLit", value: 4294967295, type: F64, loc };
@@ -271,8 +271,13 @@ export function lowerStringMethodCall(lowerer: Lowerer, call: ts.CallExpression,
     ? dynReceiver()
     : lowerMethodReceiver(lowerer, access.expression, STRING, access.name.text);
   const loc = locOf(call);
-  if ((entry.method === "indexOf" || entry.method === "includes" ||
-    entry.method === "startsWith" || entry.method === "endsWith") && call.arguments.length === 2) {
+  const searchMethod = entry.method === "indexOf" || entry.method === "includes" ||
+    entry.method === "startsWith" || entry.method === "endsWith";
+  if (searchMethod && call.arguments.length < 2) {
+    const needle = lowerStringSearchArgument(lowerer, call.arguments[0], loc);
+    return { kind: "strIntrinsic", method: entry.method, receiver, args: [needle], type: entry.result, loc };
+  }
+  if (searchMethod && call.arguments.length === 2) {
     const needle = lowerer.lowerExpr(call.arguments[0]!);
     const optionalNeedle = needle.type.kind === "union" && lowerer.runtimeOptionalWidening(needle.type, STRING) !== null;
     if (needle.type.kind !== "string" && needle.type.kind !== "dyn" && !optionalNeedle) {

packages/compiler/src/frontend/lowering/lower-builtins.ts

@@ -32,7 +32,7 @@ import {
 import { lowerAbsenceProbe } from "./lower-exprs.js";
 import { conditionalSpreadOf, lowerDynObjectLiteral } from "./expressions/object-literals.js";
 import { isSafeToDiscard } from "./expressions/evaluation-safety.js";
-import { defaultAfterUndefined, lowerOptionalArgument, lowerStaticallyUndefinedArgument } from "./optional-arguments.js";
+import { defaultAfterUndefined, lowerOptionalArgument, lowerStaticallyUndefinedArgument, lowerStringSearchArgument } from "./optional-arguments.js";
 import { HTTP2_CONSTANTS } from "./http2-constants.js";
 import { CRYPTO_CIPHERS, CRYPTO_CONSTANTS, CRYPTO_CURVES, CRYPTO_HASHES } from "./crypto-tables.js";
 import { generatorMeta, timerStyleCallback, type ParamShape } from "./lower-calls.js";
@@ -8946,19 +8946,7 @@ function staticTextDecoderEncoding(label: string): StaticTextDecoderEncoding | n
     const receiver = lowerer.lowerExprExpecting(access.expression, STRING);
     const positionNode = call.arguments[1];
     if (!positionNode) {
-      const needleNode = call.arguments[0];
-      let needle: IrExpr = strLit("undefined", loc);
-      if (needleNode) {
-        const undefinedArg = lowerStaticallyUndefinedArgument(lowerer, needleNode);
-        if (undefinedArg) {
-          needle = defaultAfterUndefined(undefinedArg, needle);
-        } else {
-          const value = lowerer.lowerExpr(needleNode);
-          needle = isUnitType(value.type)
-            ? defaultAfterUndefined(value, strLit(value.type.kind === "nullT" ? "null" : "undefined", loc))
-            : lowerer.ensureString(value, needleNode);
-        }
-      }
+      const needle = lowerStringSearchArgument(lowerer, call.arguments[0], loc);
       return { kind: "libCall", fn: "string.lastIndexOf", args: [receiver, needle], type: F64, loc };
     }
     const needle = lowerer.lowerExprExpecting(call.arguments[0]!, STRING);

packages/compiler/src/frontend/lowering/optional-arguments.ts

@@ -1,7 +1,7 @@
 import * as ts from "../ts7/adapter.js";
-import type { IrExpr, IrType } from "../../ir/ir.js";
+import type { IrExpr, IrType, SrcLoc } from "../../ir/ir.js";
 import { BOOL, F64, isUnitType, typeEquals } from "../../ir/ir.js";
-import { numLit } from "../../ir/build.js";
+import { numLit, strLit } from "../../ir/build.js";
 import type { Lowerer } from "./lowerer.js";
 import { isSafeToDiscard } from "./expressions/evaluation-safety.js";
 
@@ -43,6 +43,19 @@ export function defaultAfterUndefined(value: IrExpr, defaultValue: IrExpr): IrEx
   };
 }
 
+/** Convert an omitted or supplied string-search value after preserving its effects. */
+export function lowerStringSearchArgument(lowerer: Lowerer, node: ts.Expression | undefined, loc: SrcLoc): IrExpr {
+  const absent = strLit("undefined", loc);
+  if (!node) return absent;
+  const undefinedArg = lowerStaticallyUndefinedArgument(lowerer, node);
+  if (undefinedArg) return defaultAfterUndefined(undefinedArg, absent);
+  const value = lowerer.lowerExpr(node);
+  if (isUnitType(value.type)) {
+    return defaultAfterUndefined(value, strLit(value.type.kind === "nullT" ? "null" : "undefined", loc));
+  }
+  return lowerer.ensureString(value, node);
+}
+
 /** Lower an optional argument, applying its default only to the undefined arm. */
 export function lowerOptionalArgument(
   lowerer: Lowerer,

packages/compiler/src/frontend/lowering/surfaces.ts

@@ -382,13 +382,13 @@ export const STR_METHODS: Record<
 > = {
   charCodeAt: { method: "charCodeAt", result: F64, minArgs: 0, maxArgs: 1 },
   charAt: { method: "charAt", result: STRING, minArgs: 0, maxArgs: 1 },
-  indexOf: { method: "indexOf", result: F64, minArgs: 1, maxArgs: 2 },
+  indexOf: { method: "indexOf", result: F64, minArgs: 0, maxArgs: 2 },
   // includes with a position argument is indexOf's clamp exactly (the
   // spec routes both through StringIndexOf) — the emitter composes
   // scr_str_index_of(...) != -1 for the two-argument form.
-  includes: { method: "includes", result: BOOL, minArgs: 1, maxArgs: 2 },
-  startsWith: { method: "startsWith", result: BOOL, minArgs: 1, maxArgs: 2 },
-  endsWith: { method: "endsWith", result: BOOL, minArgs: 1, maxArgs: 2 },
+  includes: { method: "includes", result: BOOL, minArgs: 0, maxArgs: 2 },
+  startsWith: { method: "startsWith", result: BOOL, minArgs: 0, maxArgs: 2 },
+  endsWith: { method: "endsWith", result: BOOL, minArgs: 0, maxArgs: 2 },
   slice: { method: "slice", result: STRING, minArgs: 0, maxArgs: 2 },
   // substring: slice's clamp-and-swap sibling (negatives clamp to 0
   // instead of counting from the end; start > end swaps).

packages/compiler/surface-manifest.json

@@ -3511,21 +3511,21 @@
       "kind": "stdlib",
       "name": "string.prototype.endsWith",
       "status": "static",
-      "note": "the lowered call form takes 1 to 2 arguments"
+      "note": "the lowered call form takes 0 to 2 arguments"
     },
     {
       "id": "stdlib.string.includes",
       "kind": "stdlib",
       "name": "string.prototype.includes",
       "status": "static",
-      "note": "the lowered call form takes 1 to 2 arguments"
+      "note": "the lowered call form takes 0 to 2 arguments"
     },
     {
       "id": "stdlib.string.indexOf",
       "kind": "stdlib",
       "name": "string.prototype.indexOf",
       "status": "static",
-      "note": "the lowered call form takes 1 to 2 arguments"
+      "note": "the lowered call form takes 0 to 2 arguments"
     },
     {
       "id": "stdlib.string.isWellFormed",
@@ -3588,7 +3588,7 @@
       "kind": "stdlib",
       "name": "string.prototype.startsWith",
       "status": "static",
-      "note": "the lowered call form takes 1 to 2 arguments"
+      "note": "the lowered call form takes 0 to 2 arguments"
     },
     {
       "id": "stdlib.string.substring",

packages/compiler/test/ts7/baselines/order-parity.json

@@ -6967,6 +6967,12 @@
    ],
    "diags": []
   },
+  "<repo>/tests/corpus/3032-string-search-value.js": {
+   "order": [
+    "<repo>/tests/corpus/3032-string-search-value.js"
+   ],
+   "diags": []
+  },
   "<repo>/tests/corpus/304-compound-incdec.ts": {
    "order": [
     "<repo>/tests/corpus/304-compound-incdec.ts"

tests/corpus/3032-string-search-value.js

@@ -0,0 +1,36 @@
+console.log("undefined".indexOf(), "x".indexOf(), "undefined".includes(), "x".includes());
+console.log("undefined".startsWith(), "x".startsWith(), "xundefined".endsWith(), "x".endsWith());
+console.log("undefined".indexOf(undefined), "undefined".includes(void 0));
+console.log("undefined".startsWith(undefined), "undefined".endsWith(undefined));
+console.log("anullb".indexOf(null), "anullb".includes(null));
+console.log("nulla".startsWith(null), "anull".endsWith(null));
+console.log("truefalse".indexOf(true), "truefalse".includes(false));
+console.log("truefalse".startsWith(true), "truefalse".endsWith(false));
+console.log("42".indexOf(42), "42".includes(42), "42".startsWith(42), "42".endsWith(42));
+console.log("1".indexOf(1n), "1".includes(1n), "1".startsWith(1n), "1".endsWith(1n));
+
+/** @param {string | number | boolean | null | undefined} value */
+function search(value) {
+  const text = "undefined-null-1-true";
+  console.log(text.indexOf(value), text.includes(value), text.startsWith(value), text.endsWith(value));
+}
+search(undefined);
+search(null);
+search(1);
+search(true);
+search("true");
+
+let trace = "";
+function receiver() { trace += "r"; return "undefined"; }
+function needleEffect() { trace += "n"; return 1; }
+console.log(receiver().indexOf(void needleEffect()), trace);
+trace = "";
+console.log(receiver().includes(void needleEffect()), trace);
+trace = "";
+console.log(receiver().startsWith(void needleEffect()), trace);
+trace = "";
+console.log(receiver().endsWith(void needleEffect()), trace);
+
+function nullEffect() { trace += "n"; return null; }
+trace = "";
+console.log(receiver().indexOf(nullEffect()), trace);

tests/test262/upstream.json

@@ -63,6 +63,9 @@
     "test/built-ins/String/prototype/includes/coerced-values-of-position.js",
     "test/built-ins/String/prototype/includes/return-false-with-out-of-bounds-position.js",
     "test/built-ins/String/prototype/includes/return-true-if-searchstring-is-empty.js",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T4.js",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T5.js",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T7.js",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T4.js",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T5.js",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T7.js",
@@ -156,6 +159,9 @@
     "test/built-ins/String/prototype/includes/coerced-values-of-position.js": "292b6f29f5f223027deb54dafe62726790e2a61ddf2eb5e5036688b7088f105f",
     "test/built-ins/String/prototype/includes/return-false-with-out-of-bounds-position.js": "4e65326e88ae9b915771fcc70c52fd7e4aa1f7a6aa8ca047010806555b57d668",
     "test/built-ins/String/prototype/includes/return-true-if-searchstring-is-empty.js": "c5552ee08afae1dd6147d388e987a1083571d2faf18ace56b0324204d1ea50b2",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T4.js": "dee63261be6e97a1a42a9267c98b21144489caf800d6dcc3e93bde61c2cf5103",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T5.js": "b3e357871ed5fee11206e1c7ecef7c7cc094a3a2a37eacbcfbdaec600ccca754",
+    "test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T7.js": "31ee4085c1ab60c5ace3f4c4adfca8afdbc6b35d029f843fc8041d38f31a9435",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T4.js": "db9a202295d7f2f48cb023cf6774e3e23084e05dbb9f1071f4aa7e3bd93710b3",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T5.js": "fc3de1c70005ef91a3ab573220e0660255a33cf1bcf8d169d7845622747f02fe",
     "test/built-ins/String/prototype/lastIndexOf/S15.5.4.8_A1_T7.js": "d9392644874a8a2ffb6549f52aa2447d6d03c3e43762008fc6a32c18d35dea6a",

tests/test262/vendor/test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T4.js

@@ -0,0 +1,19 @@
+// Copyright 2009 the Sputnik authors.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+info: String.prototype.indexOf(searchString, position)
+es5id: 15.5.4.7_A1_T4
+description: >
+    Call indexOf(searchString, position) function without arguments of
+    string
+---*/
+
+//////////////////////////////////////////////////////////////////////////////
+//CHECK#1
+//since ToString() evaluates to "" indexOf() evaluates to indexOf("",0)
+if ("".indexOf() !== -1) {
+  throw new Test262Error('#1: "".indexOf() === -1. Actual: ' + ("".indexOf()));
+}
+//
+//////////////////////////////////////////////////////////////////////////////

tests/test262/vendor/test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T5.js

@@ -0,0 +1,23 @@
+// Copyright 2009 the Sputnik authors.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+info: String.prototype.indexOf(searchString, position)
+es5id: 15.5.4.7_A1_T5
+description: >
+    Call indexOf(searchString, position) function with null argument
+    of function object
+---*/
+
+//////////////////////////////////////////////////////////////////////////////
+//CHECK#1
+//since ToString(null) evaluates to "null" indexOf(null) evaluates to indexOf("",0)
+if (function() {
+    return "gnulluna"
+  }().indexOf(null) !== 1) {
+  throw new Test262Error('#1: function(){return "gnulluna"}().indexOf(null) === 1. Actual: ' + function() {
+    return "gnulluna"
+  }().indexOf(null));
+}
+//
+//////////////////////////////////////////////////////////////////////////////

tests/test262/vendor/test/built-ins/String/prototype/indexOf/S15.5.4.7_A1_T7.js

@@ -0,0 +1,19 @@
+// Copyright 2009 the Sputnik authors.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+info: String.prototype.indexOf(searchString, position)
+es5id: 15.5.4.7_A1_T7
+description: >
+    Call indexOf(searchString, position) function with undefined
+    argument of string object
+---*/
+
+//////////////////////////////////////////////////////////////////////////////
+//CHECK#1
+//since ToString(undefined) evaluates to "undefined" indexOf(undefined) evaluates to indexOf("undefined",0)
+if (String("undefined").indexOf(undefined) !== 0) {
+  throw new Test262Error('#1: String("undefined").indexOf(undefined) === 0. Actual: ' + String("undefined").indexOf(undefined));
+}
+//
+//////////////////////////////////////////////////////////////////////////////