@fhir-dsl/utils

Overview

@fhir-dsl/utils is the generator-internal toolbox: a tiny leveled logger, string naming helpers (toPascalCase, toCamelCase, toKebabCase, …) that the emitter uses for file names and property names, and a searchParamTypeToTs helper that turns a FHIR search-param type (string, token, …) into the matching TypeScript { type; value } literal. Anything you use to produce output that matches the generator should come from here so names stay identical.

Installation

npm install @fhir-dsl/utils

Exports

Name	Kind	One-liner
LogLevel	type	"debug" | "info" | "warn" | "error".
Logger	class	Level-gated console wrapper.
logger	const	Default singleton Logger (level info).
toPascalCase	function	"observation_category" → "ObservationCategory".
toCamelCase	function	"Observation-Category" → "observationCategory".
toKebabCase	function	"ObservationCategory" → "observation-category".
fhirTypeToFileName	function	"ObservationCategory" → "observation-category.ts".
fhirPathToPropertyName	function	"Patient.name" → "name" (strips the leading resource type and dots).
capitalizeFirst	function	"patient" → "Patient".
searchParamTypeToTs	function	Maps a search-param type ("string", "token", "date", ...) to a TS literal such as { type: "string"; value: string }.

API

LogLevel / Logger / logger

Signature

type LogLevel = "debug" | "info" | "warn" | "error";

class Logger {
  constructor(level?: LogLevel);
  debug(message: string, ...args: unknown[]): void;
  info(message: string, ...args: unknown[]): void;
  warn(message: string, ...args: unknown[]): void;
  error(message: string, ...args: unknown[]): void;
}

const logger: Logger;

Parameters

• level — Minimum level to emit. Messages below the level are dropped. Default "info".

Returns — Logger methods return void and write to console.debug / console.info / console.warn / console.error with a [LEVEL] prefix.

Example

import { Logger, logger } from "@fhir-dsl/utils";

logger.info("generating types");
const quiet = new Logger("error");
quiet.debug("this is dropped");
quiet.error("only errors escape", { attempt: 3 });

Notes — The default singleton uses info. To see generator diagnostics while debugging a build, construct your own new Logger("debug") — the logger const's level is set at construction time and there's no public setter.

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Naming helpers

Signature

function toPascalCase(str: string): string;
function toCamelCase(str: string): string;
function toKebabCase(str: string): string;
function fhirTypeToFileName(typeName: string): string;
function fhirPathToPropertyName(path: string): string;
function capitalizeFirst(str: string): string;

Example

import { toPascalCase, toCamelCase, toKebabCase, fhirTypeToFileName, fhirPathToPropertyName } from "@fhir-dsl/utils";

toPascalCase("observation-category"); // "ObservationCategory"
toCamelCase("observation_category");  // "observationCategory"
toKebabCase("ObservationCategory");   // "observation-category"
fhirTypeToFileName("Observation");    // "observation.ts"
fhirPathToPropertyName("Patient.name.given"); // "name.given"

Notes — toPascalCase does not dedupe consecutive caps; "ID" → "ID", not "Id". fhirPathToPropertyName strips the leading resource type but preserves remaining dots, which matches how the generator keys into nested paths.

---

searchParamTypeToTs

Signature

function searchParamTypeToTs(paramType: string): string;

Parameters

• paramType — One of "string", "token", "date", "reference", "quantity", "number", "uri", "composite", "special".

Returns — A TypeScript literal type string such as { type: "string"; value: string }, matching exactly what the generator emits into search-params/*.ts.

Example

import { searchParamTypeToTs } from "@fhir-dsl/utils";

searchParamTypeToTs("string");
// → "{ type: \"string\"; value: string }"

Notes — Useful when writing custom post-processing for the generator output; keeps hand-written declarations aligned with the emitter.