Function isEffectiveStrictModeSourceFile

test/fixtures/snapshot/typescript.js:15055–15087

* Returns whether the source file will be treated as if it were in strict mode at runtime.

(node, compilerOptions)

     * Returns whether the source file will be treated as if it were in strict mode at runtime.
     */
    function isEffectiveStrictModeSourceFile(node, compilerOptions) {
        // We can only verify strict mode for JS/TS files
        switch (node.scriptKind) {
            case 1 /* ScriptKind.JS */:
            case 3 /* ScriptKind.TS */:
            case 2 /* ScriptKind.JSX */:
            case 4 /* ScriptKind.TSX */:
                break;
            default:
                return false;
        }
        // Strict mode does not matter for declaration files.
        if (node.isDeclarationFile) {
            return false;
        }
        // If `alwaysStrict` is set, then treat the file as strict.
        if (getStrictOptionValue(compilerOptions, "alwaysStrict")) {
            return true;
        }
        // Starting with a "use strict" directive indicates the file is strict.
        if (ts.startsWithUseStrict(node.statements)) {
            return true;
        }
        if (ts.isExternalModule(node) || compilerOptions.isolatedModules) {
            // ECMAScript Modules are always strict.
            if (getEmitModuleKind(compilerOptions) >= ts.ModuleKind.ES2015) {
                return true;
            }
            // Other modules are strict unless otherwise specified.
            return !compilerOptions.noImplicitUseStrict;
        }
        return false;
    }
    ts.isEffectiveStrictModeSourceFile = isEffectiveStrictModeSourceFile;
    function isBlockScope(node, parentNode) {
        switch (node.kind) {