feature - dev-call show-ast-trace

src/command/dev-call/cmd.ts

@@ -3,6 +3,7 @@ import { quartoConfig } from "../../core/quarto.ts";
 import { commands } from "../command.ts";
 import { buildJsCommand } from "./build-artifacts/cmd.ts";
 import { validateYamlCommand } from "./validate-yaml/cmd.ts";
+import { showAstTraceCommand } from "./show-ast-trace/cmd.ts";
 
 type CommandOptionInfo = {
   name: string;
@@ -71,4 +72,5 @@ export const devCallCommand = new Command()
   })
   .command("cli-info", generateCliInfoCommand)
   .command("validate-yaml", validateYamlCommand)
-  .command("build-artifacts", buildJsCommand);
+  .command("build-artifacts", buildJsCommand)
+  .command("show-ast-trace", showAstTraceCommand);

src/command/dev-call/show-ast-trace/cmd.ts

@@ -0,0 +1,74 @@
+/*
+ * cmd.ts
+ *
+ * Copyright (C) 2025 Posit Software, PBC
+ */
+
+import { Command } from "cliffy/command/mod.ts";
+import { quartoCacheDir } from "../../../core/appdirs.ts";
+import { quartoConfig } from "../../../core/quarto.ts";
+import {
+  ensureDir,
+  moveSync,
+  safeRemoveDirSync,
+} from "../../../deno_ral/fs.ts";
+import { basename, dirname, join } from "../../../deno_ral/path.ts";
+import { copy } from "fs/copy";
+import { resourcePath } from "../../../core/resources.ts";
+import { execProcess } from "../../../core/process.ts";
+
+const ensureTracingToolsCopied = async () => {
+  const cacheDir = quartoCacheDir();
+  const tracingDir = `${cacheDir}/ast-tracing`;
+  await ensureDir(tracingDir);
+  safeRemoveDirSync(join(tracingDir, "qmd"), cacheDir);
+  await copy(
+    resourcePath(join("tools", "ast-tracing")),
+    join(tracingDir, "qmd"),
+  );
+  return join(tracingDir, "qmd");
+};
+
+export const showAstTraceCommand = new Command()
+  .name("show-ast-trace")
+  .hidden()
+  .arguments("<arguments...>")
+  .description(
+    "Renders the document with AST tracing enabled and then shows the debugging output.\n\n",
+  )
+  .action(async (_options: unknown, input: string, ...args: string[]) => {
+    const toolsPath = await ensureTracingToolsCopied();
+
+    const dir = dirname(input);
+    const base = basename(input, ".qmd");
+    const traceName = join(dir, `${base}-quarto-ast-trace.json`);
+
+    const renderOpts = {
+      cmd: "quarto",
+      env: {
+        "QUARTO_TRACE_FILTERS": traceName,
+      },
+      args: [
+        "render",
+        input,
+        ...args,
+        "--quiet",
+      ],
+    };
+    const _renderResult = await execProcess(renderOpts);
+    // we don't check for errors here because we want to show the trace even if
+    // the render fails
+
+    moveSync(traceName, join(toolsPath, basename(traceName)));
+
+    const _previewResult = await execProcess({
+      cmd: "quarto",
+      cwd: toolsPath,
+      args: [
+        "preview",
+        "trace-viewer.qmd",
+        "-M",
+        `trace_1:${basename(traceName)}`,
+      ],
+    });
+  });