fix: harden core build system against silent failures

- Wrap rebuild() in try/finally to guarantee mutex release (prevents deadlock)
- Surface rebuild errors via .catch() instead of discarding with void
- Add null checks for vfile.data.relativePath (prevents crash on virtual files)
- Add try-finally for worker pool cleanup in parse.ts (prevents thread leaks)
- Remove process.exit(1) from parse error handler (let errors propagate)
- Add per-emitter error handling in emit phase with degraded-build warning
- Replace unsafe Map.get()! assertions with null-checked access in config-loader

quartz/build.ts

@@ -124,7 +124,12 @@ async function startWatching(
 
   for (const content of initialContent) {
     const [_tree, vfile] = content
-    contentMap.set(vfile.data.relativePath!, {
+    const relPath = vfile.data.relativePath
+    if (!relPath) {
+      console.warn(`Skipping file with no relativePath: ${vfile.path}`)
+      continue
+    }
+    contentMap.set(relPath, {
       type: "markdown",
       content,
     })
@@ -165,19 +170,25 @@ async function startWatching(
       fp = toPosixPath(fp)
       if (buildData.ignored(fp)) return
       changes.push({ path: fp as FilePath, type: "add" })
-      void rebuild(changes, clientRefresh, buildData)
+      rebuild(changes, clientRefresh, buildData).catch((err) => {
+        console.error(styleText("red", "Rebuild failed:"), err.message ?? err)
+      })
     })
     .on("change", (fp) => {
       fp = toPosixPath(fp)
       if (buildData.ignored(fp)) return
       changes.push({ path: fp as FilePath, type: "change" })
-      void rebuild(changes, clientRefresh, buildData)
+      rebuild(changes, clientRefresh, buildData).catch((err) => {
+        console.error(styleText("red", "Rebuild failed:"), err.message ?? err)
+      })
     })
     .on("unlink", (fp) => {
       fp = toPosixPath(fp)
       if (buildData.ignored(fp)) return
       changes.push({ path: fp as FilePath, type: "delete" })
-      void rebuild(changes, clientRefresh, buildData)
+      rebuild(changes, clientRefresh, buildData).catch((err) => {
+        console.error(styleText("red", "Rebuild failed:"), err.message ?? err)
+      })
     })
 
   return async () => {
@@ -194,147 +205,155 @@ async function rebuild(changes: ChangeEvent[], clientRefresh: () => void, buildD
   buildData.lastBuildMs = new Date().getTime()
   const numChangesInBuild = changes.length
   const release = await mut.acquire()
-
-  // if there's another build after us, release and let them do it
-  if (ctx.buildId !== buildId) {
-    release()
-    return
-  }
-
-  const perf = new PerfTimer()
-  perf.addEvent("rebuild")
-  console.log(styleText("yellow", "Detected change, rebuilding..."))
-
-  // update changesSinceLastBuild
-  for (const change of changes) {
-    changesSinceLastBuild[change.path] = change.type
-  }
-
-  const staticResources = getStaticResourcesFromPlugins(ctx)
-  const pathsToParse: FilePath[] = []
-  for (const [fp, type] of Object.entries(changesSinceLastBuild)) {
-    if (type === "delete" || path.extname(fp) !== ".md") continue
-    const fullPath = joinSegments(argv.directory, toPosixPath(fp)) as FilePath
-    pathsToParse.push(fullPath)
-  }
-
-  const parsed = await parseMarkdown(ctx, pathsToParse)
-  for (const content of parsed) {
-    contentMap.set(content[1].data.relativePath!, {
-      type: "markdown",
-      content,
-    })
-  }
-
-  // update state using changesSinceLastBuild
-  // we do this weird play of add => compute change events => remove
-  // so that partialEmitters can do appropriate cleanup based on the content of deleted files
-  for (const [file, change] of Object.entries(changesSinceLastBuild)) {
-    if (change === "delete") {
-      // universal delete case
-      contentMap.delete(file as FilePath)
+  try {
+    // if there's another build after us, release and let them do it
+    if (ctx.buildId !== buildId) {
+      return
     }
 
-    // manually track non-markdown files as processed files only
-    // contains markdown files
-    if (change === "add" && path.extname(file) !== ".md") {
-      contentMap.set(file as FilePath, {
-        type: "other",
+    const perf = new PerfTimer()
+    perf.addEvent("rebuild")
+    console.log(styleText("yellow", "Detected change, rebuilding..."))
+
+    // update changesSinceLastBuild
+    for (const change of changes) {
+      changesSinceLastBuild[change.path] = change.type
+    }
+
+    const staticResources = getStaticResourcesFromPlugins(ctx)
+    const pathsToParse: FilePath[] = []
+    for (const [fp, type] of Object.entries(changesSinceLastBuild)) {
+      if (type === "delete" || path.extname(fp) !== ".md") continue
+      const fullPath = joinSegments(argv.directory, toPosixPath(fp)) as FilePath
+      pathsToParse.push(fullPath)
+    }
+
+    const parsed = await parseMarkdown(ctx, pathsToParse)
+    for (const content of parsed) {
+      const relPath = content[1].data.relativePath
+      if (!relPath) {
+        console.warn(`Skipping file with no relativePath: ${content[1].path}`)
+        continue
+      }
+      contentMap.set(relPath, {
+        type: "markdown",
+        content,
       })
     }
-  }
 
-  const changeEvents: ChangeEvent[] = Object.entries(changesSinceLastBuild).map(([fp, type]) => {
-    const path = fp as FilePath
-    const processedContent = contentMap.get(path)
-    if (processedContent?.type === "markdown") {
-      const [_tree, file] = processedContent.content
+    // update state using changesSinceLastBuild
+    // we do this weird play of add => compute change events => remove
+    // so that partialEmitters can do appropriate cleanup based on the content of deleted files
+    for (const [file, change] of Object.entries(changesSinceLastBuild)) {
+      if (change === "delete") {
+        // universal delete case
+        contentMap.delete(file as FilePath)
+      }
+
+      // manually track non-markdown files as processed files only
+      // contains markdown files
+      if (change === "add" && path.extname(file) !== ".md") {
+        contentMap.set(file as FilePath, {
+          type: "other",
+        })
+      }
+    }
+
+    const changeEvents: ChangeEvent[] = Object.entries(changesSinceLastBuild).map(([fp, type]) => {
+      const path = fp as FilePath
+      const processedContent = contentMap.get(path)
+      if (processedContent?.type === "markdown") {
+        const [_tree, file] = processedContent.content
+        return {
+          type,
+          path,
+          file,
+        }
+      }
+
       return {
         type,
         path,
-        file,
+      }
+    })
+
+    // update allFiles and then allSlugs with the consistent view of content map
+    ctx.allFiles = Array.from(contentMap.keys())
+    ctx.allSlugs = ctx.allFiles.map((fp) => slugifyFilePath(fp as FilePath))
+
+    const markdownContent = Array.from(contentMap.values())
+      .filter((file) => file.type === "markdown")
+      .map((file) => file.content)
+    reportSlugCollisions(markdownContent)
+    let processedFiles = filterContent(ctx, markdownContent)
+
+    let emittedFiles = 0
+
+    // Phase 1: Run PageTypeDispatcher first so it populates ctx.virtualPages
+    const dispatcher = cfg.plugins.emitters.find((e) => e.name === "PageTypeDispatcher")
+    if (dispatcher) {
+      ctx.virtualPages = []
+      const emitFn = dispatcher.partialEmit ?? dispatcher.emit
+      const emitted = await emitFn(ctx, processedFiles, staticResources, changeEvents)
+      if (emitted !== null) {
+        if (Symbol.asyncIterator in emitted) {
+          for await (const file of emitted) {
+            emittedFiles++
+            if (ctx.argv.verbose) {
+              console.log(`[emit:${dispatcher.name}] ${file}`)
+            }
+          }
+        } else {
+          emittedFiles += emitted.length
+          if (ctx.argv.verbose) {
+            for (const file of emitted) {
+              console.log(`[emit:${dispatcher.name}] ${file}`)
+            }
+          }
+        }
       }
     }
 
-    return {
-      type,
-      path,
-    }
-  })
+    // Phase 2: Run all other emitters with content extended by virtual pages
+    const contentWithVirtual =
+      ctx.virtualPages.length > 0 ? [...processedFiles, ...ctx.virtualPages] : processedFiles
+    for (const emitter of cfg.plugins.emitters) {
+      if (emitter.name === "PageTypeDispatcher") continue
+      // Try to use partialEmit if available, otherwise assume the output is static
+      const emitFn = emitter.partialEmit ?? emitter.emit
+      const emitted = await emitFn(ctx, contentWithVirtual, staticResources, changeEvents)
+      if (emitted === null) {
+        continue
+      }
 
-  // update allFiles and then allSlugs with the consistent view of content map
-  ctx.allFiles = Array.from(contentMap.keys())
-  ctx.allSlugs = ctx.allFiles.map((fp) => slugifyFilePath(fp as FilePath))
-
-  const markdownContent = Array.from(contentMap.values())
-    .filter((file) => file.type === "markdown")
-    .map((file) => file.content)
-  reportSlugCollisions(markdownContent)
-  let processedFiles = filterContent(ctx, markdownContent)
-
-  let emittedFiles = 0
-
-  // Phase 1: Run PageTypeDispatcher first so it populates ctx.virtualPages
-  const dispatcher = cfg.plugins.emitters.find((e) => e.name === "PageTypeDispatcher")
-  if (dispatcher) {
-    ctx.virtualPages = []
-    const emitFn = dispatcher.partialEmit ?? dispatcher.emit
-    const emitted = await emitFn(ctx, processedFiles, staticResources, changeEvents)
-    if (emitted !== null) {
       if (Symbol.asyncIterator in emitted) {
+        // Async generator case
         for await (const file of emitted) {
           emittedFiles++
           if (ctx.argv.verbose) {
-            console.log(`[emit:${dispatcher.name}] ${file}`)
+            console.log(`[emit:${emitter.name}] ${file}`)
           }
         }
       } else {
+        // Array case
         emittedFiles += emitted.length
         if (ctx.argv.verbose) {
           for (const file of emitted) {
-            console.log(`[emit:${dispatcher.name}] ${file}`)
+            console.log(`[emit:${emitter.name}] ${file}`)
           }
         }
       }
     }
+
+    console.log(
+      `Emitted ${emittedFiles} files to \`${argv.output}\` in ${perf.timeSince("rebuild")}`,
+    )
+    console.log(styleText("green", `Done rebuilding in ${perf.timeSince()}`))
+    changes.splice(0, numChangesInBuild)
+    clientRefresh()
+  } finally {
+    release()
   }
-
-  // Phase 2: Run all other emitters with content extended by virtual pages
-  const contentWithVirtual =
-    ctx.virtualPages.length > 0 ? [...processedFiles, ...ctx.virtualPages] : processedFiles
-  for (const emitter of cfg.plugins.emitters) {
-    if (emitter.name === "PageTypeDispatcher") continue
-    // Try to use partialEmit if available, otherwise assume the output is static
-    const emitFn = emitter.partialEmit ?? emitter.emit
-    const emitted = await emitFn(ctx, contentWithVirtual, staticResources, changeEvents)
-    if (emitted === null) {
-      continue
-    }
-
-    if (Symbol.asyncIterator in emitted) {
-      // Async generator case
-      for await (const file of emitted) {
-        emittedFiles++
-        if (ctx.argv.verbose) {
-          console.log(`[emit:${emitter.name}] ${file}`)
-        }
-      }
-    } else {
-      // Array case
-      emittedFiles += emitted.length
-      if (ctx.argv.verbose) {
-        for (const file of emitted) {
-          console.log(`[emit:${emitter.name}] ${file}`)
-        }
-      }
-    }
-  }
-
-  console.log(`Emitted ${emittedFiles} files to \`${argv.output}\` in ${perf.timeSince("rebuild")}`)
-  console.log(styleText("green", `Done rebuilding in ${perf.timeSince()}`))
-  changes.splice(0, numChangesInBuild)
-  clientRefresh()
-  release()
 }
 
 export default async (argv: Argv, mut: Mutex, clientRefresh: () => void) => {

quartz/plugins/loader/config-loader.ts

@@ -854,10 +854,13 @@ function resolveGroups(
         const groupConfig = groups[item.group]
         groupPriority.set(item.group, groupConfig?.priority ?? item.priority)
       }
-      groupedComponents.get(item.group)!.push({
-        component: item.component,
-        groupOptions: item.groupOptions,
-      })
+      const groupMembers = groupedComponents.get(item.group)
+      if (groupMembers) {
+        groupMembers.push({
+          component: item.component,
+          groupOptions: item.groupOptions,
+        })
+      }
     }
   }
 
@@ -873,7 +876,8 @@ function resolveGroups(
       if (processedGroups.has(item.group)) continue
       processedGroups.add(item.group)
 
-      const members = groupedComponents.get(item.group)!
+      const members = groupedComponents.get(item.group)
+      if (!members) continue
       const groupConfig = groups[item.group] ?? {}
 
       const flexComponents = members.map((m) => ({
@@ -896,7 +900,7 @@ function resolveGroups(
         gap: groupConfig.gap ?? "1rem",
       }) as QuartzComponent
 
-      entries.push({ priority: groupPriority.get(item.group)!, component: flexComponent })
+      entries.push({ priority: groupPriority.get(item.group) ?? 50, component: flexComponent })
     } else {
       entries.push({ priority: item.priority, component: item.component })
     }

quartz/processors/emit.ts

@@ -78,12 +78,23 @@ export async function emitContent(ctx: BuildCtx, content: ProcessedContent[]) {
   const otherEmitters = cfg.plugins.emitters.filter(
     (e) => e.name !== "PageTypeDispatcher" && e.name !== "ComponentResources",
   )
+  let emitErrors = 0
   const counts = await Promise.all(
     otherEmitters.map((emitter) =>
-      runEmitter(emitter, ctx, contentWithVirtual, staticResources, log),
+      runEmitter(emitter, ctx, contentWithVirtual, staticResources, log).catch((err) => {
+        emitErrors++
+        console.error(`Emitter "${emitter.name}" failed:`, err.message ?? err)
+        return 0
+      }),
     ),
   )
   emittedFiles += counts.reduce((sum, c) => sum + c, 0)
 
+  if (emitErrors > 0) {
+    console.warn(
+      `\nBuild completed with ${emitErrors} emitter failure(s). Output may be incomplete.`,
+    )
+  }
+
   log.end(`Emitted ${emittedFiles} files to \`${argv.output}\` in ${perf.timeSince()}`)
 }

quartz/processors/parse.ts

@@ -171,11 +171,6 @@ export async function parseMarkdown(ctx: BuildCtx, fps: FilePath[]): Promise<Pro
       maxWorkers: concurrency,
       workerType: "thread",
     })
-    const errorHandler = (err: any) => {
-      console.error(err)
-      process.exit(1)
-    }
-
     const serializableCtx: WorkerSerializableBuildCtx = {
       buildId: ctx.buildId,
       argv: ctx.argv,
@@ -185,37 +180,40 @@ export async function parseMarkdown(ctx: BuildCtx, fps: FilePath[]): Promise<Pro
       virtualPages: [],
     }
 
-    const textToMarkdownPromises: WorkerPromise<MarkdownContent[]>[] = []
-    let processedFiles = 0
-    for (const chunk of chunks(fps, CHUNK_SIZE)) {
-      textToMarkdownPromises.push(pool.exec("parseMarkdown", [serializableCtx, chunk]))
+    try {
+      const textToMarkdownPromises: WorkerPromise<MarkdownContent[]>[] = []
+      let processedFiles = 0
+      for (const chunk of chunks(fps, CHUNK_SIZE)) {
+        textToMarkdownPromises.push(pool.exec("parseMarkdown", [serializableCtx, chunk]))
+      }
+
+      const mdResults: Array<MarkdownContent[]> = await Promise.all(
+        textToMarkdownPromises.map(async (promise) => {
+          const result = await promise
+          processedFiles += result.length
+          log.updateText(`text->markdown ${styleText("gray", `${processedFiles}/${fps.length}`)}`)
+          return result
+        }),
+      )
+
+      const markdownToHtmlPromises: WorkerPromise<ProcessedContent[]>[] = []
+      processedFiles = 0
+      for (const mdChunk of mdResults) {
+        markdownToHtmlPromises.push(pool.exec("processHtml", [serializableCtx, mdChunk]))
+      }
+      const results: ProcessedContent[][] = await Promise.all(
+        markdownToHtmlPromises.map(async (promise) => {
+          const result = await promise
+          processedFiles += result.length
+          log.updateText(`markdown->html ${styleText("gray", `${processedFiles}/${fps.length}`)}`)
+          return result
+        }),
+      )
+
+      res = results.flat()
+    } finally {
+      await pool.terminate()
     }
-
-    const mdResults: Array<MarkdownContent[]> = await Promise.all(
-      textToMarkdownPromises.map(async (promise) => {
-        const result = await promise
-        processedFiles += result.length
-        log.updateText(`text->markdown ${styleText("gray", `${processedFiles}/${fps.length}`)}`)
-        return result
-      }),
-    ).catch(errorHandler)
-
-    const markdownToHtmlPromises: WorkerPromise<ProcessedContent[]>[] = []
-    processedFiles = 0
-    for (const mdChunk of mdResults) {
-      markdownToHtmlPromises.push(pool.exec("processHtml", [serializableCtx, mdChunk]))
-    }
-    const results: ProcessedContent[][] = await Promise.all(
-      markdownToHtmlPromises.map(async (promise) => {
-        const result = await promise
-        processedFiles += result.length
-        log.updateText(`markdown->html ${styleText("gray", `${processedFiles}/${fps.length}`)}`)
-        return result
-      }),
-    ).catch(errorHandler)
-
-    res = results.flat()
-    await pool.terminate()
   }
 
   log.end(`Parsed ${res.length} Markdown files in ${perf.timeSince()}`)