openidea/src/platform/javaLaunch.ts

/**
 * Java "Application" run configurations, shared by Run and Debug: the command
 * line is `java [vm options] -cp ${classpath} <main class> [program args]`;
 * `${classpath}` (or `${testClasspath}`) and the `java` launcher are resolved
 * through jdtls when the configuration starts.
 */
import { call, commands, IpcError, type JavaLaunchInfo, type RunConfig, type RequestId } from "@/platform/ipc";
import { tx } from "@/platform/i18n";

export const CLASSPATH = "${classpath}";
export const TEST_CLASSPATH = "${testClasspath}";
/** Run configuration kinds launched as a JVM main class. */
export const JVM_APPLICATION_KINDS = ["application", "spring-boot"];

export function isJvmApplication(config: Pick<RunConfig, "kind">): boolean {
  return JVM_APPLICATION_KINDS.includes(config.kind);
}

/** `java` options whose value is the next argument. */
const WITH_VALUE = new Set([
  "-cp",
  "-classpath",
  "--class-path",
  "-p",
  "--module-path",
  "--upgrade-module-path",
  "--add-modules",
  "--add-opens",
  "--add-exports",
  "--add-reads",
  "--patch-module",
  "--limit-modules",
  "--enable-native-access",
]);

export interface JavaCommandLine {
  /** VM options, without the classpath. */
  vmArgs: string[];
  mainClass: string | null;
  programArgs: string[];
  /** Which classpath placeholder the configuration uses (`null`: an explicit classpath or none). */
  classpath: "runtime" | "test" | null;
  /** An explicit `-cp` value other than a placeholder. */
  explicitClasspath: string | null;
}

/** Splits `java` arguments into VM options, main class and program arguments. */
export function parseJavaArgs(args: readonly string[]): JavaCommandLine {
  const vmArgs: string[] = [];
  let classpath: JavaCommandLine["classpath"] = null;
  let explicitClasspath: string | null = null;
  for (let i = 0; i < args.length; i++) {
    const a = args[i]!;
    if (a === "-cp" || a === "-classpath" || a === "--class-path") {
      const value = args[++i] ?? "";
      if (value === CLASSPATH) classpath = "runtime";
      else if (value === TEST_CLASSPATH) classpath = "test";
      else explicitClasspath = value;
      continue;
    }
    if (WITH_VALUE.has(a)) {
      vmArgs.push(a, args[++i] ?? "");
      continue;
    }
    if (a.startsWith("-")) {
      vmArgs.push(a);
      continue;
    }
    return { vmArgs, mainClass: a, programArgs: args.slice(i + 1), classpath, explicitClasspath };
  }
  return { vmArgs, mainClass: null, programArgs: [], classpath, explicitClasspath };
}

/** The configuration with its placeholders and launcher resolved. */
export function resolveJavaCommand(config: RunConfig, info: JavaLaunchInfo): RunConfig {
  const cp = info.classPaths.join(info.pathListSeparator);
  const args: string[] = [];
  if (info.modulePaths.length && !config.args.some((a) => a === "-p" || a === "--module-path"))
    args.push("--module-path", info.modulePaths.join(info.pathListSeparator));
  args.push(...config.args.map((a) => (a === CLASSPATH || a === TEST_CLASSPATH ? cp : a)));
  const command = config.command === "java" && info.javaExec ? info.javaExec : config.command;
  return { ...config, command, args };
}

/** Console report of a launch's compile errors (`path:line:col: error: …`) and their likely causes; "" when none. */
export function formatCompileErrors(info: JavaLaunchInfo): string {
  const lines = info.errors.map((e) => `${e.path}:${e.line}:${e.column}: error: ${e.message}`);
  const more = info.errorCount - info.errors.length;
  if (more > 0) lines.push(`… and ${more} more error${more === 1 ? "" : "s"} (see the Problems tool window)`);
  lines.push(...info.hints);
  return lines.length ? `${lines.join("\n")}\n` : "";
}

/** Joins arguments into one string for adapters that take `args` / `vmArgs` as text (java-debug). */
export function joinJavaArgs(args: readonly string[]): string {
  return args.map((a) => (a === "" ? '""' : /[\s"]/.test(a) ? `"${a.replace(/(["\\])/g, "\\$1")}"` : a)).join(" ");
}

/** JDWP agent options: listen on a free local port and wait for the debugger. */
export const JDWP_AGENT = "-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=127.0.0.1:0";

/** The port of `Listening for transport dt_socket at address: 5005` (JDWP's start-up line). */
export function jdwpListeningPort(line: string): number | null {
  const m = /Listening for transport dt_socket at address:\s*(?:[\w.[\]:-]*:)?(\d+)\s*$/.exec(line.trim());
  return m ? Number(m[1]) : null;
}

/**
 * Module directory (relative to the project root, `""` for the root) of a JVM
 * source file: the part before `src/{main,test}/…`, else the working directory
 * of the closest Maven / Gradle configuration.
 */
export function jvmModuleDir(relPath: string, configs: readonly RunConfig[] = []): string {
  const m = /^(?:(.*)\/)?src\/(?:main|test|[\w-]+)\/(?:java|kotlin|scala|groovy)\//.exec(relPath);
  if (m) return m[1] ?? "";
  const cwds = configs
    .filter((c) => c.kind === "maven" || c.kind === "gradle")
    .map((c) => (c.cwd ?? "").replace(/^\.\/?/, "").replace(/\/+$/, ""))
    .filter((cwd) => !cwd || relPath.startsWith(cwd + "/"))
    .sort((a, b) => b.length - a.length);
  return cwds[0] ?? "";
}

/** Recover the classpath module of configurations saved before it was stored separately. */
export async function findJavaModule(config: RunConfig): Promise<string | null> {
  if (config.module != null) return config.module;
  const main = parseJavaArgs(config.args).mainClass;
  if (!main) return null;
  const outer = main.split("$")[0]!;
  const simple = outer.slice(outer.lastIndexOf(".") + 1);
  const pkg = outer.slice(0, Math.max(0, outer.lastIndexOf(".")));
  const names = [`${simple}.java`, `${simple}.kt`, ...(simple.endsWith("Kt") ? [`${simple.slice(0, -2)}.kt`] : [])];
  const matches = (await Promise.all(names.map((name) => call(commands.findFiles(name, 1000)))))
    .flat()
    .filter((file) => names.includes(file.relPath.split("/").pop()!));
  const configs = await call(commands.runConfigs());
  const modules = new Set<string>();
  for (const file of matches) {
    const text = await call(commands.fsReadText(file.path));
    const sourcePackage = /^\s*package\s+([\w.]+)\s*[;\r\n]/m.exec(text)?.[1] ?? "";
    if (sourcePackage === pkg) modules.add(jvmModuleDir(file.relPath, configs));
  }
  return modules.size === 1 ? [...modules][0]! : null;
}

export async function resolveJavaModule(config: RunConfig): Promise<string> {
  const module = await findJavaModule(config);
  if (module === null)
    throw new Error(tx`Cannot determine the module for main class '${parseJavaArgs(config.args).mainClass}'`);
  return module;
}

/** Shared, cancellable build and classpath preparation for Run and Debug. */
export interface JavaPreparation {
  request: RequestId;
  signal: AbortSignal;
  report?: (text: string, kind?: "system" | "stderr") => void;
}

export async function prepareJavaLaunch(config: RunConfig, preparation: JavaPreparation) {
  const { signal, report } = preparation;
  signal.throwIfAborted();
  const parsed = parseJavaArgs(config.args);
  if (!parsed.mainClass) throw new Error(`No main class in '${config.name}'`);
  report?.(tx`Building and resolving the classpath of ${parsed.mainClass}…` + "\n");
  const started = performance.now();
  const module = await resolveJavaModule(config);
  signal.throwIfAborted();
  const moduleMs = performance.now() - started;
  const info = await call(
    commands.javaResolveLaunch(module, parsed.classpath === "test", true, preparation.request),
  ).catch((error: unknown) => {
    if (
      error instanceof IpcError &&
      error.kind !== "cancelled" &&
      /^jdtls:.*(?:does not belong to any java project|references non-existing project|not a java project)/i.test(
        error.message,
      )
    )
      throw new Error(
        tx`Java module '${module || "."}' is not imported. Wait for Java project import to finish. If it still fails, check the run configuration's module and whether it is included in the parent Maven or Gradle build, or open its folder as a project.`,
      );
    throw error;
  });
  signal.throwIfAborted();
  console.info("Java launch preparation", { module, moduleMs, resolveMs: performance.now() - started - moduleMs });
  if (info.build === "withErrors")
    report?.(tx("Build completed with errors; launching with the last compiled classes.") + "\n", "stderr");
  if (info.build === "failed") report?.(tx("Build failed; launching with the last compiled classes.") + "\n", "stderr");
  const errors = formatCompileErrors(info);
  if (errors) report?.(errors, "stderr");
  if (parsed.classpath && !info.classPaths.length)
    throw new Error(tx("The classpath is empty: is the module imported by the Java language server?"));
  return { module, info, resolved: resolveJavaCommand(config, info) };
}