@theguild/federation-composition/esm/supergraph/validation/rules/satisfiablity/contexts.js

Open Source Composition library for Apollo Federation

export class Contexts {
    bitByContext = new Map();
    byTypeName = new Map();
    constructor(supergraphState) {
        this.addUnionContexts(supergraphState);
        for (const type of supergraphState.objectTypes.values()) {
            this.addTypeContexts(supergraphState, type);
        }
        for (const type of supergraphState.interfaceTypes.values()) {
            this.addTypeContexts(supergraphState, type);
        }
    }
    maskOf(context) {
        return this.bitFor(context);
    }
    maskFor(contexts) {
        let mask = 0n;
        for (const context of contexts) {
            mask |= this.bitFor(context);
        }
        return mask;
    }
    bitFor(context) {
        let bit = this.bitByContext.get(context);
        if (bit === undefined) {
            bit = 1n << BigInt(this.bitByContext.size);
            this.bitByContext.set(context, bit);
        }
        return bit;
    }
    addMask(typeName, mask) {
        if (mask === 0n) {
            return;
        }
        const existing = this.byTypeName.get(typeName) ?? 0n;
        this.byTypeName.set(typeName, existing | mask);
    }
    addUnionContexts(supergraphState) {
        for (const union of supergraphState.unionTypes.values()) {
            const mask = this.maskFor(union.contexts);
            for (const member of union.members) {
                this.addMask(member, mask);
            }
        }
    }
    addTypeContexts(supergraphState, type) {
        let mask = this.maskFor(type.contexts);
        for (const interfaceName of type.interfaces) {
            const interfaceType = supergraphState.interfaceTypes.get(interfaceName);
            if (interfaceType) {
                mask |= this.maskFor(interfaceType.contexts);
            }
        }
        this.addMask(type.name, mask);
    }
}