fix(config): preserve quoted strings when stripping JSONC trailing commas

src/services/jsonc.ts

@@ -76,10 +76,51 @@ export function stripJsoncComments(content: string): string {
       continue;
     }
 
+    // Drop structural trailing commas (comma before } or ], allowing
+    // whitespace and comments in between).
+    if (char === "," && isTrailingComma(content, i)) {
+      i++;
+      continue;
+    }
+
     result += char;
     i++;
   }
 
-  // Remove trailing commas before } or ]
-  return result.replace(/,\s*([}\]])/g, "$1");
+  return result;
+}
+
+/** True when the comma at `commaIndex` is followed only by whitespace/comments then } or ]. */
+function isTrailingComma(content: string, commaIndex: number): boolean {
+  let next = commaIndex + 1;
+  while (next < content.length) {
+    const c = content.charAt(next);
+    const n = content.charAt(next + 1);
+
+    if (/\s/.test(c)) {
+      next++;
+      continue;
+    }
+
+    if (c === "/" && n === "/") {
+      next += 2;
+      while (next < content.length && content.charAt(next) !== "\n") next++;
+      continue;
+    }
+
+    if (c === "/" && n === "*") {
+      next += 2;
+      while (
+        next + 1 < content.length &&
+        !(content.charAt(next) === "*" && content.charAt(next + 1) === "/")
+      ) {
+        next++;
+      }
+      next += 2;
+      continue;
+    }
+
+    return c === "}" || c === "]";
+  }
+  return false;
 }

tests/config-resolution.test.ts

@@ -1,5 +1,7 @@
 import { afterEach, describe, expect, it, spyOn } from "bun:test";
 import * as fs from "node:fs";
+import { buildMemoryProviderConfig } from "../src/services/ai/provider-config.js";
+import { applySafeExtraParams } from "../src/services/ai/providers/base-provider.js";
 import {
   initConfig,
   CONFIG,
@@ -53,6 +55,28 @@ describe("project-scoped config resolution", () => {
     expect(CONFIG.opencodeModel).toBe("project-model");
   });
 
+  it("preserves JSONC string values through configuration loading and provider parameters", () => {
+    existsSpy = spyOn(fs, "existsSync").mockImplementation((p: unknown) =>
+      normalizePath(p).includes(".config/opencode/opencode-mem")
+    );
+    readSpy = spyOn(fs, "readFileSync").mockReturnValue(`{
+      "storagePath": "/tmp/cache,]v2",
+      "memoryModel": "local-model",
+      "memoryApiUrl": "https://example.invalid/v1",
+      "memoryApiKey": "fixture-only-key",
+      "memoryExtraParams": {"stop": [",}", ",]",],},
+    }`);
+
+    initConfig("/some/project");
+
+    expect(CONFIG.storagePath).toBe("/tmp/cache,]v2");
+    expect(CONFIG.memoryExtraParams).toEqual({ stop: [",}", ",]"] });
+    const providerConfig = buildMemoryProviderConfig(CONFIG);
+    const requestBody: Record<string, unknown> = {};
+    applySafeExtraParams(requestBody, providerConfig.extraParams ?? {});
+    expect(requestBody.stop).toEqual([",}", ",]"]);
+  });
+
   it("keeps automatic cleanup policy under global configuration", () => {
     existsSpy = spyOn(fs, "existsSync").mockReturnValue(true);
     readSpy = spyOn(fs, "readFileSync").mockImplementation((p) => {

tests/jsonc.test.ts

@@ -0,0 +1,39 @@
+import { describe, expect, it } from "bun:test";
+import { stripJsoncComments } from "../src/services/jsonc.js";
+
+describe("JSONC string preservation", () => {
+  for (const value of [",}", ",]", ", }", ", ]", 'say "a, }b"', "\\path,]end"]) {
+    it(`preserves ${JSON.stringify(value)} inside string values and keys`, () => {
+      const expected = { [value]: value };
+      expect(JSON.parse(stripJsoncComments(JSON.stringify(expected)))).toEqual(expected);
+    });
+  }
+
+  it("handles escaped backslashes before a closing quote", () => {
+    const expected = { path: "C:\\cache\\", next: "value" };
+    expect(JSON.parse(stripJsoncComments(JSON.stringify(expected)))).toEqual(expected);
+  });
+
+  it("keeps comment-like text inside strings", () => {
+    const expected = { url: "https://example.invalid/a//b", text: "/* keep, } */" };
+    expect(JSON.parse(stripJsoncComments(JSON.stringify(expected)))).toEqual(expected);
+  });
+
+  it("removes structural trailing commas separated by comments and whitespace", () => {
+    const input = `{
+      // A line comment
+      "stop": [",}", ",]", /* before array end */ ],
+      "nested": {"enabled": true, // before object end
+      },
+    }`;
+    expect(JSON.parse(stripJsoncComments(input))).toEqual({
+      stop: [",}", ",]"],
+      nested: { enabled: true },
+    });
+  });
+
+  it("keeps ordinary separators between array and object entries", () => {
+    const expected = { first: [1, 2, 3], second: { a: true, b: false } };
+    expect(JSON.parse(stripJsoncComments(JSON.stringify(expected)))).toEqual(expected);
+  });
+});