@squiz/json-schema-library/lib/resolveAllOf.ts

Customizable and hackable json-validator and json-schema utilities for traversal, data generation and validation

/**
 * resolveAllOf is tricky:
 *
 * resolve all merges all schemas altough each schema in the list must be used
 * for validation. But to use this as a template schema to create data and a
 * resolved schema, structural data must be merged. Currently, it is merged in
 * all case, but separately validated and resolved. This will break at some
 * point, requiring us to be more specific on our current intent (validation
 * vs get (resolved) schema)
 */
import copy from "./utils/copy";
import { JSONSchema, JSONPointer, JSONError } from "./types";
import { Draft } from "./draft";
import { mergeArraysUnique } from "./utils/merge";

/**
 * resolves schema
 * when complete this will have much duplication to step.object etc
 */
function resolveSchema(draft: Draft, schemaToResolve: JSONSchema, data: unknown): JSONSchema {
    const schema = { ...(draft.resolveRef(schemaToResolve) ?? {}) };

    // @draft >= 07
    if (schema.if && (schema.then || schema.else)) {
        const isValid = draft.isValid(data, schema.if);
        if (isValid && schema.then) {
            return resolveSchema(draft, schema.then, data);
        }
        if (!isValid && schema.else) {
            return resolveSchema(draft, schema.else, data);
        }

        delete schema.if;
        delete schema.then;
        delete schema.else;
    }

    return schema;
}

export default function resolveAllOf(
    draft: Draft,
    data: any,
    schema: JSONSchema = draft.rootSchema,
    pointer: JSONPointer = "#"
): JSONSchema | JSONError {
    let mergedSchema = copy(schema);
    for (let i = 0; i < schema.allOf.length; i += 1) {
        const allOfSchema = resolveSchema(draft, schema.allOf[i], data);
        mergedSchema = mergeArraysUnique(mergedSchema, allOfSchema);
        data = draft.getTemplate(data, mergedSchema);
    }
    delete mergedSchema.allOf;
    return mergedSchema;
}