fix(cli): tunnel moc exit code so compiler crashes are distinguishable

cli/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Next
 
+- `mops build`, `mops check`, `mops generate`, and `mops check-stable` now tunnel `moc`'s exit code instead of always exiting `1`. moc exits `2` on a compiler crash (uncaught internal error) versus `1` for normal user errors (type/compile errors, stable-compat mismatch, bad args), so CI and scripts can now distinguish "file a Motoko bug" from "fix your code" via `$?`. `mops test` likewise exits `2` when a `moc` process crashes during a test run, instead of reporting it as an ordinary test failure.
+
 ## 2.16.0
 
 - `mops bench` now compiles benchmark canisters under **enhanced orthogonal persistence** (moc's default) instead of forcing `--legacy-persistence` — measuring the persistence mode real canisters run. Pass `--legacy-persistence` to opt back into legacy persistence.

cli/commands/build.ts

@@ -4,7 +4,7 @@ import { exists } from "fs-extra";
 import { mkdir, readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import { lock, unlockSync } from "proper-lockfile";
-import { cliError } from "../error.js";
+import { cliError, cliExit } from "../error.js";
 import { isCandidCompatible } from "../helpers/is-candid-compatible.js";
 import {
   filterCanisters,
@@ -136,7 +136,8 @@ export async function build(
               console.error(result.stdout);
             }
           }
-          cliError(
+          cliExit(
+            result.exitCode ?? 1,
             `Build failed for canister ${canisterName} (exit code: ${result.exitCode})`,
           );
         }

cli/commands/check-stable.ts

@@ -3,7 +3,7 @@ import { existsSync, mkdirSync, mkdtempSync } from "node:fs";
 import { rm } from "node:fs/promises";
 import chalk from "chalk";
 import { execa } from "execa";
-import { cliError } from "../error.js";
+import { cliError, cliExit } from "../error.js";
 import {
   getCheckLimitPendingIssue,
   prepareMigrationArgs,
@@ -261,7 +261,8 @@ export async function runStableCheck(
       if (result.stderr) {
         console.error(result.stderr);
       }
-      cliError(
+      cliExit(
+        result.exitCode ?? 1,
         `✗ Stable compatibility check failed for canister '${canisterName}'`,
       );
     }
@@ -314,7 +315,8 @@ async function generateStableTypes(
     if (result.stderr) {
       console.error(result.stderr);
     }
-    cliError(
+    cliExit(
+      result.exitCode ?? 1,
       `Failed to generate stable types for ${moFile} (exit code: ${result.exitCode})`,
     );
   }

cli/commands/check.ts

@@ -1,7 +1,7 @@
 import path from "node:path";
 import chalk from "chalk";
 import { execa } from "execa";
-import { cliError } from "../error.js";
+import { cliError, cliExit } from "../error.js";
 import {
   getGlobalMocArgs,
   getRootDir,
@@ -208,7 +208,8 @@ async function checkCanisters(
         });
 
         if (result.exitCode !== 0) {
-          cliError(
+          cliExit(
+            result.exitCode ?? 1,
             `✗ Check failed for canister ${canisterName} (exit code: ${result.exitCode})`,
           );
         }
@@ -285,7 +286,8 @@ async function checkFiles(
       });
 
       if (result.exitCode !== 0) {
-        cliError(
+        cliExit(
+          result.exitCode ?? 1,
           `✗ Check failed for file ${file} (exit code: ${result.exitCode})`,
         );
       }

cli/commands/generate.ts

@@ -2,7 +2,7 @@ import chalk from "chalk";
 import { execa } from "execa";
 import { mkdir } from "node:fs/promises";
 import path from "node:path";
-import { cliError } from "../error.js";
+import { cliError, cliExit } from "../error.js";
 import {
   filterCanisters,
   resolveCanisterConfigs,
@@ -104,7 +104,8 @@ export async function generateCandid(
             console.error(result.stdout);
           }
         }
-        cliError(
+        cliExit(
+          result.exitCode ?? 1,
           `Failed to generate Candid for canister ${canisterName} (exit code: ${result.exitCode})`,
         );
       }

cli/commands/test/test.ts

@@ -159,14 +159,21 @@ export async function test(filter = "", options: Partial<TestOptions> = {}) {
       explicitReplica,
     );
     if (!passed) {
-      process.exit(1);
+      process.exit(maxMocExit >= 2 ? 2 : 1);
     }
   }
 }
 
 let mocPath = "";
 let wasmtimePath = "";
 
+let maxMocExit = 0;
+const trackMocExit = (code: number | null) => {
+  if (code && code >= 2) {
+    maxMocExit = Math.max(maxMocExit, code);
+  }
+};
+
 async function runAll(
   reporterName: ReporterName | undefined,
   filter = "",
@@ -197,6 +204,7 @@ export async function testWithReporter(
   signal?: AbortSignal,
   explicitReplica = false,
 ): Promise<boolean> {
+  maxMocExit = 0;
   let rootDir = getRootDir();
   let files: string[] = [];
   let libFiles = globSync("**/test?(s)/lib.mo", MOTOKO_GLOB_CONFIG);
@@ -328,7 +336,7 @@ export async function testWithReporter(
           }
           throw error;
         });
-        pipeMMF(proc, mmf).then(resolve);
+        pipeMMF(proc, mmf, trackMocExit).then(resolve);
       }
       // build and run wasm
       else if (mode === "wasi") {
@@ -346,7 +354,7 @@ export async function testWithReporter(
           }
           throw error;
         });
-        pipeMMF(buildProc, mmf)
+        pipeMMF(buildProc, mmf, trackMocExit)
           .then(async () => {
             if (mmf.failed > 0) {
               return;
@@ -413,7 +421,7 @@ export async function testWithReporter(
           throw error;
         });
 
-        pipeMMF(buildProc, mmf)
+        pipeMMF(buildProc, mmf, trackMocExit)
           .then(async () => {
             if (mmf.failed > 0) {
               return;

cli/commands/test/utils.ts

@@ -68,18 +68,22 @@ export function pipeStderrToMMF(stderr: Readable, mmf: MMF1, dir = "") {
   });
 }
 
-export function pipeMMF(proc: ChildProcessWithoutNullStreams, mmf: MMF1) {
+export function pipeMMF(
+  proc: ChildProcessWithoutNullStreams,
+  mmf: MMF1,
+  onClose?: (code: number | null) => void,
+) {
   return new Promise<void>((resolve) => {
     pipeStdoutToMMF(proc.stdout, mmf);
     pipeStderrToMMF(proc.stderr, mmf);
 
-    // exit
     proc.on("close", (code) => {
       if (code === 0) {
         mmf.strategy !== "print" && mmf.pass();
       } else if (code !== 1) {
         mmf.fail(`unknown exit code: ${code}`);
       }
+      onClose?.(code ?? null);
       resolve();
     });
   });

cli/error.ts

@@ -4,3 +4,8 @@ export function cliError(...args: unknown[]): never {
   console.error(chalk.red(...args));
   process.exit(1);
 }
+
+export function cliExit(code: number, ...args: unknown[]): never {
+  console.error(chalk.red(...args));
+  process.exit(code || 1);
+}