startsWith-endsWith.js

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function toLatin1(s) {

    assertEq(isLatin1(s), true);

    return s;

function testStartsWith() {

    var s1 = toLatin1("abc\u0099def");

    var s2 = toLatin1("abc\u0099d");

    var s3 = toLatin1("abc\u0098d");

    var s4 = toLatin1("bc\u0099");

    // Latin1 + Latin1

    assertEq(s1.startsWith(s2), true);

    assertEq(s1.startsWith(s3), false);

    assertEq(s1.startsWith(s4), false);

    assertEq(s1.startsWith(s4, 1), true);

    assertEq(s1.startsWith(s1), true);

    // Latin1 + TwoByte

    assertEq(s1.startsWith("abc\u0099\u1200".slice(0, -1)), true);

    assertEq(s1.startsWith("abc\u0099e\u1200".slice(0, -1)), false);

    assertEq(s1.startsWith("bc\u0099\u1200".slice(0, -1), 1), true);

    assertEq(s1.startsWith("\u1200"), false);

    // TwoByte + Latin1

    var s5 = "abc\u0099de\u1200";

    assertEq(s5.startsWith(s1), false);

    assertEq(s5.startsWith(s2), true);

    assertEq(s5.startsWith(s4), false);

    assertEq(s5.startsWith(s4, 1), true);

    // TwoByte + TwoByte

    assertEq(s5.startsWith(s5), true);

    assertEq(s5.startsWith("\u1200"), false);

    assertEq(s5.startsWith("\u1200", 6), true);

testStartsWith();

function testEndsWith() {

    var s1 = toLatin1("zabc\u0099defg");

    var s2 = toLatin1("\u0099defg");

    var s3 = toLatin1("\u0098defg");

    var s4 = toLatin1("zabc\u0099def");

    // Latin1 + Latin1

    assertEq(s1.endsWith(s2), true);

    assertEq(s1.endsWith(s3), false);

    assertEq(s1.endsWith(s4), false);

    assertEq(s1.endsWith(s4, 8), true);

    assertEq(s1.endsWith(s1), true);

    // Latin1 + TwoByte

    assertEq(s1.endsWith("abc\u0099defg\u1200".slice(0, -1)), true);

    assertEq(s1.endsWith("\u1100efg\u1200".slice(0, -1)), false);

    assertEq(s1.endsWith("bc\u0099\u1200".slice(0, -1), 5), true);

    assertEq(s1.endsWith("\u1200"), false);

    // TwoByte + Latin1

    var s5 = "\u1200zabc\u0099defg";

    assertEq(s5.endsWith(s1), true);

    assertEq(s5.endsWith(s2), true);

    assertEq(s5.endsWith(s4), false);

    assertEq(s5.endsWith(s4, 9), true);

    // TwoByte + TwoByte

    assertEq(s5.endsWith(s5), true);

    assertEq(s5.endsWith("\u1200"), false);

    assertEq(s5.endsWith("\u1200za", 3), true);

testEndsWith();