tools: make apilinks building more robust

1. Move the apilinks.json file into out/doc so it gets cleaned when
  running `make docclean`
2. When the apilinks.json generated is empty, throw a specific error
  so it's easier to understand what's wrong
3. Write to a file passed through CLI arguments instead writing to
  stdout in apilinks.js so the build process is more robust in
  the case of a bad binary

PR-URL: https://github.com/nodejs/node/pull/25019
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

2 files changed, 10 insertions, 5 deletions

diff --git a/tools/doc/apilinks.js b/tools/doc/apilinks.js
index c86db14338..9c23ae55c5 100644
--- a/tools/doc/apilinks.js
+++ b/tools/doc/apilinks.js
@@ -47,7 +47,9 @@ const tag = execSync(`git describe --contains ${hash}`).split('\n')[0] || hash;
 
 // Extract definitions from each file specified.
 const definition = {};
-process.argv.slice(2).forEach((file) => {
+const output = process.argv[2];
+const inputs = process.argv.slice(3);
+inputs.forEach((file) => {
   const basename = path.basename(file, '.js');
 
   // Parse source.
@@ -206,4 +208,4 @@ process.argv.slice(2).forEach((file) => {
   }
 });
 
-console.log(JSON.stringify(definition, null, 2));
+fs.writeFileSync(output, JSON.stringify(definition, null, 2), 'utf8');
diff --git a/tools/doc/generate.js b/tools/doc/generate.js
index 7ca47e2ae0..dd213a35a6 100644
--- a/tools/doc/generate.js
+++ b/tools/doc/generate.js
@@ -49,9 +49,12 @@ args.forEach(function(arg) {
   } else if (arg.startsWith('--output-directory=')) {
     outputDir = arg.replace(/^--output-directory=/, '');
   } else if (arg.startsWith('--apilinks=')) {
-    apilinks = JSON.parse(
-      fs.readFileSync(arg.replace(/^--apilinks=/, ''), 'utf8')
-    );
+    const linkFile = arg.replace(/^--apilinks=/, '');
+    const data = fs.readFileSync(linkFile, 'utf8');
+    if (!data.trim()) {
+      throw new Error(`${linkFile} is empty`);
+    }
+    apilinks = JSON.parse(data);
   }
 });