addMissingDeclareProperty.ts

import {
    codeFixAll,
    createCodeFixAction,
    registerCodeFix,
} from "../_namespaces/ts.codefix.js";
import {
    Diagnostics,
    getTokenAtPosition,
    isIdentifier,
    Node,
    SourceFile,
    SyntaxKind,
    textChanges,
    tryAddToSet,
} from "../_namespaces/ts.js";

const fixId = "addMissingDeclareProperty";
const errorCodes = [
    Diagnostics.Property_0_will_overwrite_the_base_property_in_1_If_this_is_intentional_add_an_initializer_Otherwise_add_a_declare_modifier_or_remove_the_redundant_declaration.code,
];

registerCodeFix({
    errorCodes,
    getCodeActions: function getCodeActionsToAddMissingDeclareOnProperty(context) {
        const changes = textChanges.ChangeTracker.with(context, t => makeChange(t, context.sourceFile, context.span.start));
        if (changes.length > 0) {
            return [createCodeFixAction(fixId, changes, Diagnostics.Prefix_with_declare, fixId, Diagnostics.Prefix_all_incorrect_property_declarations_with_declare)];
        }
    },
    fixIds: [fixId],
    getAllCodeActions: context => {
        const fixedNodes = new Set<Node>();
        return codeFixAll(context, errorCodes, (changes, diag) => makeChange(changes, diag.file, diag.start, fixedNodes));
    },
});

function makeChange(changeTracker: textChanges.ChangeTracker, sourceFile: SourceFile, pos: number, fixedNodes?: Set<Node>) {
    const token = getTokenAtPosition(sourceFile, pos);
    if (!isIdentifier(token)) {
        return;
    }
    const declaration = token.parent;
    if (
        declaration.kind === SyntaxKind.PropertyDeclaration &&
        (!fixedNodes || tryAddToSet(fixedNodes, declaration))
    ) {
        changeTracker.insertModifierBefore(sourceFile, SyntaxKind.DeclareKeyword, declaration);
    }
}