chore: import upstream snapshot with attribution

tests/unit/compression/rtk-code-stripper.test.ts

@@ -0,0 +1,135 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+
+import {
+  applyRtkCompression,
+  detectCodeLanguage,
+  stripCode,
+} from "../../../open-sse/services/compression/index.ts";
+
+describe("RTK code stripper", () => {
+  it("detects common code languages", () => {
+    assert.equal(detectCodeLanguage("interface User { id: string }"), "typescript");
+    assert.equal(detectCodeLanguage("def run():\n    print('x')"), "python");
+    assert.equal(detectCodeLanguage('fn main() { println!("x"); }'), "rust");
+    assert.equal(detectCodeLanguage("package main\nfunc main() {}"), "go");
+    assert.equal(detectCodeLanguage("class Main { }"), "java");
+  });
+
+  it("preserves comments and string literals safely", () => {
+    const js = stripCode(
+      "// comment\nconst url = 'https://example.com/a//b';\n/* block */\nconsole.log(url);",
+      "javascript"
+    );
+
+    assert.ok(js.text.includes("// comment"));
+    assert.ok(js.text.includes("https://example.com/a//b"));
+    assert.ok(js.text.includes("/* block */"));
+  });
+
+  it("preserves Python docstrings and comments", () => {
+    const result = stripCode('"""doc"""\n# comment\nprint("ok")', "python", {
+      preserveDocstrings: true,
+    });
+
+    assert.ok(result.text.includes("doc"));
+    assert.ok(result.text.includes("# comment"));
+  });
+
+  it("applies to fenced code blocks through RTK runtime", () => {
+    const body = {
+      messages: [
+        {
+          role: "assistant",
+          content: `Before.
+
+\`\`\`txt
+${Array.from({ length: 20 }, () => "same code line").join("\n")}
+\`\`\`
+
+After.`,
+        },
+      ],
+    };
+    const result = applyRtkCompression(body, {
+      config: {
+        enabled: true,
+        intensity: "standard",
+        applyToToolResults: false,
+        applyToAssistantMessages: false,
+        applyToCodeBlocks: true,
+        enabledFilters: [],
+        disabledFilters: [],
+        maxLinesPerResult: 100,
+        maxCharsPerResult: 12000,
+        deduplicateThreshold: 3,
+      },
+    });
+
+    assert.equal(result.compressed, true);
+    const serialized = JSON.stringify(result.body.messages);
+    assert.match(serialized, /Before/);
+    assert.match(serialized, /After/);
+    assert.match(serialized, /same code line/);
+    assert.match(serialized, /\[rtk:dropped/);
+    assert.ok(result.stats?.techniquesUsed.includes("rtk-code-strip"));
+  });
+
+  it("does not compress non-code text when only code block compression is enabled", () => {
+    const content = Array.from({ length: 20 }, () => "same prose line").join("\n");
+    const body = {
+      messages: [{ role: "assistant", content }],
+    };
+    const result = applyRtkCompression(body, {
+      config: {
+        enabled: true,
+        intensity: "standard",
+        applyToToolResults: false,
+        applyToAssistantMessages: false,
+        applyToCodeBlocks: true,
+        enabledFilters: [],
+        disabledFilters: [],
+        maxLinesPerResult: 100,
+        maxCharsPerResult: 12000,
+        deduplicateThreshold: 3,
+      },
+    });
+
+    assert.equal(result.compressed, false);
+    assert.deepEqual(result.body, body);
+  });
+
+  it("does not compress fenced code when code block compression is disabled", () => {
+    const body = {
+      messages: [
+        {
+          role: "assistant",
+          content: `Before.
+
+\`\`\`txt
+${Array.from({ length: 20 }, () => "same code line").join("\n")}
+\`\`\`
+
+After.`,
+        },
+      ],
+    };
+    const result = applyRtkCompression(body, {
+      config: {
+        enabled: true,
+        intensity: "standard",
+        applyToToolResults: false,
+        applyToAssistantMessages: false,
+        applyToCodeBlocks: false,
+        enabledFilters: [],
+        disabledFilters: [],
+        maxLinesPerResult: 100,
+        maxCharsPerResult: 12000,
+        deduplicateThreshold: 3,
+      },
+    });
+
+    assert.equal(result.compressed, false);
+    assert.deepEqual(result.body, body);
+  });
+});