Set up back end to recollect information from pnpm

src/api/dependency-discovery/env.local

@@ -0,0 +1,6 @@
+# Environment variables needed if you want to run `npm run dev`
+# and run the server locally, outside of Docker. For all the various
+# ways we run this using Docker, the env is defined by one of the
+# config/env.* files in the root.  This requires that the other
+# services are running, particularly the login and users services.
+DEP_DISCOVERY_PORT=10500

src/api/dependency-discovery/package.json

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+{
+  "name": "dependency-discovery",
+  "private": true,
+  "version": "0.1.0",
+  "description": "A dependency graph compilation service for Telescope",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "start": "node src/server.js",
+    "dev": "env-cmd -f env.local nodemon src/server.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/Seneca-CDOT/telescope.git"
+  },
+  "author": "",
+  "license": "BSD-2-Clause",
+  "bugs": {
+    "url": "https://github.com/Seneca-CDOT/telescope/issues"
+  },
+  "homepage": "https://github.com/Seneca-CDOT/telescope#readme",
+  "dependencies": {
+    "@senecacdot/satellite": "^1.x"
+  },
+  "devDependencies": {
+    "env-cmd": "10.1.0",
+    "nodemon": "2.0.15"
+  }
+}

src/api/dependency-discovery/src/dependency-list.js

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+const { readFile } = require('fs/promises');
+const { join } = require('path');
+const { cwd } = require('process');
+
+async function getDependencies() {
+  const dependencies = await readFile(join(cwd(), 'deps.txt'), 'utf8');
+
+  // The order of the alternatives is important!
+  // The regex engine will favor the first pattern on an alternation
+  // even if the other alternatives are subpatterns
+  return dependencies.split(/\r\n|\n|\r/).filter((line) => line !== '');
+}
+
+module.exports = getDependencies();

src/api/dependency-discovery/src/index.js

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+const { Satellite } = require('@senecacdot/satellite');
+
+const dependenciesRoute = require('./router');
+
+const service = new Satellite();
+
+service.router.use('/', dependenciesRoute);
+
+module.exports = service;

src/api/dependency-discovery/src/router.js

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+const { Router } = require('@senecacdot/satellite');
+const dependencyList = require('./dependency-list');
+
+const router = Router();
+
+router.get('/projects', async (req, res, next) => {
+  try {
+    res.set('Cache-Control', 'max-age=3600');
+    res.status(200).json(await dependencyList);
+  } catch (err) {
+    next(err);
+  }
+});
+
+module.exports = router;

src/api/dependency-discovery/src/server.js

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+const service = require('.');
+
+const port = parseInt(process.env.DEP_DISCOVERY_PORT || 10500, 10);
+
+service.start(port);

tools/pnpm-deps-gen.sh

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+#!/bin/bash
+
+# First regex can be read as the following:
+# .*\.pnpm\/(@?[^@]+).*
+# We use the literal .pnpm to find the start of the package name
+# After that, we use the pattern "@?[^@]+" to search for the name
+# that appears first, instead of ".+".
+#
+# Sometimes we could have foo@1.0.0_bar@1.0.0, in which case we want
+# to capture foo. With ".+", we could capture foo@1.0.0_bar.
+# Instead, we search for the string of characters that do not include
+# "@", which translates to "[^@]+". However, some package names include
+# @ at the start, so we cover that case, as well.
+
+set -e
+
+option=$1
+filename=$2
+
+if [[ $# -eq 2 && $option = "-o" && $filename ]]; then
+  echo "Start collecting dependencies"
+  pnpm list -w -r --parseable --depth=0 | sed -n -r -e "s|.*\.pnpm/(@?[^@]+).*|\1|p" -e "s/+/\//" | sort -u > $filename
+  echo "Dependencies collected"
+else
+  echo "command usage: $BASH_SOURCE -o filename"
+fi