test: tighten local retry recovery assertions

test/e2e-obsidian/runner/localFileRetryAssertions.ts

@@ -0,0 +1,24 @@
+/** Decoded database fields inspected by the plain-text local retry scenarios. */
+export interface DatabaseTextObservation {
+    /** Metadata type reported by the loaded revision. */
+    readonly type?: unknown;
+    /** Content datatype reported by the database reader. */
+    readonly datatype?: unknown;
+    /** Concatenated revision content, before any encoding assumption. */
+    readonly body?: unknown;
+}
+
+/**
+ * Match the exact text and representation required by the Markdown fixtures.
+ * @param observation - The loaded database branch, or an unavailable observation.
+ * @param expected - Exact text expected from the corresponding Vault file.
+ * @returns True only for plain Metadata and plain content with exactly the expected text.
+ * @remarks This closure-free function is also serialised into the isolated Obsidian evaluation.
+ * Base64 characters stored as plain text are different bytes, even when they encode the expected text.
+ */
+export function matchesPlainDatabaseText(
+    observation: DatabaseTextObservation | null | undefined,
+    expected: string
+): boolean {
+    return observation?.type === "plain" && observation.datatype === "plain" && observation.body === expected;
+}