packages/okam-build/lib/processor/index.js
function getImportFilterModules(usedFilters, scriptFile, buildManager) {
    if (!usedFilters) {
        return;
    }

    let filterModules = [];
    let {file: filterFile, filterNames: definedFilters} = scriptFile.filters || {};
    let hasFilterUsed = definedFilters && usedFilters.some(item => {
        if (definedFilters.includes(item)) {
            return true;
        }
        return false;
    });

    if (!hasFilterUsed) {
        return filterModules;
    }

    if (filterFile) {
        let src = relative(filterFile.path, scriptFile.dirname);
        if (src.charAt(0) !== '.') {
            src = './' + src;
        }
        filterModules.push({src, filters: definedFilters});
    }
    else {
        filterModules.push({filters: definedFilters});
    }

    return filterModules;
}
function getImportFilterModules(usedFilters, scriptFile, buildManager) {
    if (!usedFilters) {
        return;
    }

    let filterModules = [];
    let {file: filterFile, filterNames: definedFilters} = scriptFile.filters || {};
    let hasFilterUsed = definedFilters && usedFilters.some(item => {
        if (definedFilters.includes(item)) {
            return true;
        }
        return false;
    });

    if (!hasFilterUsed) {
        return filterModules;
    }

    if (filterFile) {
        let src = relative(filterFile.path, scriptFile.dirname);
        if (src.charAt(0) !== '.') {
            src = './' + src;
        }
        filterModules.push({src, filters: definedFilters});
    }
    else {
        filterModules.push({filters: definedFilters});
    }

    return filterModules;
}
Get need to import filter modules

@inner
@param {Array.<string>} usedFilters the used filter names
@param {Object} scriptFile the script file to declare the local filter
@param {BuildManager} buildManager the build manager
@return {?Array.<Object>}