test: add comprehensive prompt.ts unit tests

Tests cover promptLanguageInstruction, promptSchemaExample,
renderPromptTemplate, and buildPrompts edge cases including
auto language, truncation markers, custom prompt variable
substitution, card count normalization, and fallback behavior.

Change-Id: I75d5b354df15456ddbd08d9d21846f74d6b6cea3

package.json

@@ -10,7 +10,7 @@
     "typecheck": "tsc --noEmit",
     "lint": "biome check main.ts src/",
     "lint:fix": "biome check --write main.ts src/",
-    "test": "npm run build && npm run typecheck && node tests/main.test.js && node tests/generation-job-manager.test.js && node tests/anchor.test.js && node tests/schema.test.js && node tests/cache.test.js && node tests/cards-nav.test.js && node tests/markdown.test.js && node tests/vault-batch.test.js && node tests/i18n.test.js && node tests/scroll.test.js && node tests/settings.test.js && node tests/providers.test.js && node tests/streaming.test.js && node tests/cli.test.js && node tests/direct-cache.test.js && node tests/direct-providers.test.js && node tests/direct-settings.test.js && node tests/direct-i18n.test.js && node tests/direct-streaming.test.js"
+    "test": "npm run build && npm run typecheck && node tests/main.test.js && node tests/generation-job-manager.test.js && node tests/anchor.test.js && node tests/schema.test.js && node tests/cache.test.js && node tests/cards-nav.test.js && node tests/markdown.test.js && node tests/vault-batch.test.js && node tests/i18n.test.js && node tests/scroll.test.js && node tests/settings.test.js && node tests/providers.test.js && node tests/streaming.test.js && node tests/cli.test.js && node tests/direct-prompt.test.js && node tests/direct-cache.test.js && node tests/direct-providers.test.js && node tests/direct-settings.test.js && node tests/direct-i18n.test.js && node tests/direct-streaming.test.js"
   },
   "devDependencies": {
     "@biomejs/biome": "^2.4.13",

tests/direct-prompt.test.js

@@ -0,0 +1,97 @@
+const { assert, requireBundledModule, cleanup } = require('./direct-test-setup');
+
+(async () => {
+  try {
+    const prompt = await requireBundledModule('src/prompt.ts');
+    const settings = await requireBundledModule('src/settings.ts');
+    const base = { ...settings.DEFAULT_SETTINGS, promptLanguage: 'en', minCards: 3, maxCards: 7 };
+
+    // ── promptLanguageInstruction ──
+    assert.strictEqual(prompt.promptLanguageInstruction('en'), 'Write title, gist, and bullets in English.');
+    assert.strictEqual(prompt.promptLanguageInstruction('zh'), '用中文输出 title、gist 和 bullets。');
+    assert.strictEqual(prompt.promptLanguageInstruction('auto'), 'Write title, gist, and bullets in the main language of the source document.');
+    assert.strictEqual(prompt.promptLanguageInstruction('fr'), '用中文输出 title、gist 和 bullets。', 'unknown language falls to zh');
+
+    // ── promptSchemaExample ──
+    const enExample = prompt.promptSchemaExample('en');
+    assert.ok(enExample.includes('U-shaped gains'), 'en example has expected title');
+    assert.ok(enExample.includes('"cards"'), 'en example is JSON-like');
+
+    const zhExample = prompt.promptSchemaExample('zh');
+    assert.ok(zhExample.includes('U 型收益曲线'), 'zh example has expected title');
+    assert.ok(zhExample.includes('"cards"'), 'zh example is JSON-like');
+
+    assert.ok(prompt.promptSchemaExample('auto').includes('U 型收益曲线'), 'auto falls to zh example');
+
+    // ── renderPromptTemplate ──
+    assert.strictEqual(prompt.renderPromptTemplate('Hello {name}!', { name: 'World' }), 'Hello World!');
+    assert.strictEqual(prompt.renderPromptTemplate('{a} and {b}', { a: 1, b: 2 }), '1 and 2', 'numeric vars');
+    assert.strictEqual(prompt.renderPromptTemplate('{missing}', {}), '{missing}', 'unmatched placeholder preserved');
+    assert.strictEqual(prompt.renderPromptTemplate('no vars', {}), 'no vars', 'no placeholders');
+    assert.strictEqual(prompt.renderPromptTemplate('', { a: 1 }), '', 'empty template');
+    assert.strictEqual(prompt.renderPromptTemplate(null, { a: 1 }), '', 'null template returns empty string');
+
+    // ── buildPrompts: basic en ──
+    const enResult = prompt.buildPrompts('Hello world', base);
+    assert.ok(enResult.system.includes('3-7'), 'en card range in system');
+    assert.ok(enResult.system.includes('English'), 'en language instruction');
+    assert.ok(enResult.user.includes('Source document:'), 'en user prefix');
+    assert.ok(enResult.user.includes('Hello world'), 'en content');
+
+    // ── buildPrompts: basic zh ──
+    const zhResult = prompt.buildPrompts('你好', { ...base, promptLanguage: 'zh' });
+    assert.ok(zhResult.system.includes('3-7'), 'zh card range');
+    assert.ok(zhResult.system.includes('中文'), 'zh language instruction');
+    assert.ok(zhResult.user.includes('以下是需要处理的文档全文'), 'zh user prefix');
+
+    // ── buildPrompts: auto language ──
+    const autoResult = prompt.buildPrompts('content', { ...base, promptLanguage: 'auto' });
+    assert.ok(autoResult.system.includes('main language'), 'auto language instruction');
+
+    // ── buildPrompts: truncation ──
+    const longDoc = 'x'.repeat(25000);
+    const truncResult = prompt.buildPrompts(longDoc, { ...base, maxDocChars: 20000 });
+    assert.ok(truncResult.user.includes('[Document truncated]'), 'en truncation marker');
+    assert.ok(truncResult.user.length < 25000, 'content truncated');
+
+    const zhTrunc = prompt.buildPrompts(longDoc, { ...base, promptLanguage: 'zh', maxDocChars: 20000 });
+    assert.ok(zhTrunc.user.includes('[文档过长，已截断]'), 'zh truncation marker');
+
+    // ── buildPrompts: custom system prompt ──
+    const custom = prompt.buildPrompts('doc', {
+      ...base,
+      customSystemPrompt: 'Custom: {minCards}-{maxCards} cards. {languageInstruction}',
+    });
+    assert.ok(custom.system.includes('Custom: 3-7 cards'), 'custom template vars substituted');
+    assert.ok(custom.system.includes('Non-overridable output contract'), 'contract appended');
+    assert.ok(!custom.system.includes('long-form reading'), 'default prompt NOT included when custom set');
+
+    // ── buildPrompts: empty custom prompt uses default ──
+    const emptyCustom = prompt.buildPrompts('doc', { ...base, customSystemPrompt: '' });
+    assert.ok(emptyCustom.system.includes('long-form reading'), 'default prompt used when custom is empty');
+
+    // ── buildPrompts: whitespace-only custom prompt uses default ──
+    const wsCustom = prompt.buildPrompts('doc', { ...base, customSystemPrompt: '   ' });
+    assert.ok(wsCustom.system.includes('long-form reading'), 'default prompt used when custom is whitespace-only');
+
+    // ── buildPrompts: invalid promptLanguage falls back ──
+    const badLang = prompt.buildPrompts('doc', { ...base, promptLanguage: 'xyz' });
+    assert.ok(badLang.system.includes('中文'), 'invalid promptLanguage falls back to zh default');
+
+    // ── buildPrompts: card count normalization ──
+    // 0 is falsy so || picks DEFAULT (5), then Math.max(1, 5) = 5
+    const zeroCards = prompt.buildPrompts('doc', { ...base, minCards: 0, maxCards: 0 });
+    assert.ok(zeroCards.system.includes('5-'), 'zero minCards falls back to default');
+
+    const bigCards = prompt.buildPrompts('doc', { ...base, minCards: 5, maxCards: 3 });
+    assert.ok(bigCards.system.includes('5-5'), 'maxCards raised to match minCards');
+
+    // ── buildPrompts: maxDocChars normalization ──
+    const defaultMax = prompt.buildPrompts('doc', { ...base, maxDocChars: undefined });
+    assert.ok(defaultMax.user.includes('doc'), 'undefined maxDocChars uses default without truncation');
+
+    console.log('direct prompt tests passed');
+  } finally {
+    cleanup();
+  }
+})().catch((e) => { console.error(e); process.exit(1); });