fix(section): preserve user-defined subscription order in UCI and backend

tests/subscription_section_order.sh

@@ -0,0 +1,162 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+TACHYON_LIB="${TACHYON_LIB:-$ROOT_DIR/tachyon/files/usr/lib}"
+WORK_DIR="$(mktemp -d)"
+
+cleanup() {
+  rm -rf "$WORK_DIR"
+}
+trap cleanup EXIT
+
+fail() {
+  printf 'FAIL: %s\n' "$1" >&2
+  exit 1
+}
+
+# 1. Create a mock uci state with 3 subscriptions in a section, where UCI file order is sub1, sub2, sub3,
+# but order options specify: sub2 (order 0), sub3 (order 1), sub1 (order 2)
+cat >"$WORK_DIR/uci.uc" <<'UCODE'
+let state = {
+    tachyon: {
+        sec1: {
+            ".name": "sec1",
+            ".type": "section",
+            action: "connection",
+            enabled: "1"
+        },
+        sub1: {
+            ".name": "sub1",
+            ".type": "subscription_url",
+            section: "sec1",
+            url: "https://example.com/third.txt",
+            order: "2"
+        },
+        sub2: {
+            ".name": "sub2",
+            ".type": "subscription_url",
+            section: "sec1",
+            url: "https://example.com/first.txt",
+            order: "0"
+        },
+        sub3: {
+            ".name": "sub3",
+            ".type": "subscription_url",
+            section: "sec1",
+            url: "https://example.com/second.txt",
+            order: "1"
+        }
+    }
+};
+
+function cursor() {
+    return {
+        load: function(_package_name) {
+            return true;
+        },
+        foreach: function(package_name, type_name, callback) {
+            let pkg = state["" + package_name] || {};
+            for (let name in pkg) {
+                let section = pkg[name];
+                if (section && section[".type"] == type_name) {
+                    callback(section);
+                }
+            }
+        }
+    };
+}
+
+return { cursor };
+UCODE
+
+ucode -L "$WORK_DIR" -L "$TACHYON_LIB" -e '
+let connections = require("config.connections");
+let cursor = require("uci").cursor();
+
+function assert(val, msg) {
+    if (!val) {
+        warn("Assertion failed: " + msg + "\n");
+        exit(1);
+    }
+}
+
+let index = connections.item_index_from_cursor(cursor, "tachyon");
+connections.set_item_sections_from_cursor(cursor, "tachyon");
+
+let sec = { ".name": "sec1", action: "connection" };
+let urls = connections.subscription_urls(sec);
+
+assert(length(urls) == 3, "expected 3 subscription urls, got " + length(urls));
+assert(urls[0] == "https://example.com/first.txt", "expected first url at index 0, got " + urls[0]);
+assert(urls[1] == "https://example.com/second.txt", "expected second url at index 1, got " + urls[1]);
+assert(urls[2] == "https://example.com/third.txt", "expected third url at index 2, got " + urls[2]);
+'
+
+# 2. Test fallback when items do not have order option: they should maintain their original order
+cat >"$WORK_DIR/uci_no_order.uc" <<'UCODE'
+let state = {
+    tachyon: {
+        sec1: {
+            ".name": "sec1",
+            ".type": "section",
+            action: "connection",
+            enabled: "1"
+        },
+        subA: {
+            ".name": "subA",
+            ".type": "subscription_url",
+            section: "sec1",
+            url: "https://example.com/alpha.txt"
+        },
+        subB: {
+            ".name": "subB",
+            ".type": "subscription_url",
+            section: "sec1",
+            url: "https://example.com/beta.txt"
+        }
+    }
+};
+
+function cursor() {
+    return {
+        load: function(_package_name) {
+            return true;
+        },
+        foreach: function(package_name, type_name, callback) {
+            let pkg = state["" + package_name] || {};
+            for (let name in pkg) {
+                let section = pkg[name];
+                if (section && section[".type"] == type_name) {
+                    callback(section);
+                }
+            }
+        }
+    };
+}
+
+return { cursor };
+UCODE
+
+ucode -L "$WORK_DIR" -L "$TACHYON_LIB" -e '
+let connections = require("config.connections");
+let cursor = require("uci_no_order").cursor();
+
+function assert(val, msg) {
+    if (!val) {
+        warn("Assertion failed: " + msg + "\n");
+        exit(1);
+    }
+}
+
+connections.set_item_sections_from_cursor(cursor, "tachyon");
+
+let sec = { ".name": "sec1", action: "connection" };
+let urls = connections.subscription_urls(sec);
+
+assert(length(urls) == 2, "expected 2 subscription urls");
+assert(urls[0] == "https://example.com/alpha.txt", "expected alpha first");
+assert(urls[1] == "https://example.com/beta.txt", "expected beta second");
+'
+
+echo "PASS: subscription_section_order"