Merge commit 'ac30fbd' into HEAD

* fix(desktop): read JSON with deeply nested overwritten values

* fix(desktop): bound exported JSON construction by view depth

* fix(desktop): preserve deep JSON numeric facts within bounded memory

---------

Co-authored-by: morluto <[email protected]>

docs/desktop-application-export.md

@@ -310,8 +310,8 @@ entry it does not read. The module reads the central directory itself, as REA
 does, and shows `zipfile` only the records it lists, reading each entry in
 bounded chunks no further than a byte past its declared size. A JSON file
 holding a number JavaScript cannot read exactly, such as an integer above 2^53,
-or nested more than 500 levels deep, gets an `error` instead of a view, as in
-REA, while text that is not one JSON
+or whose retained value nests more than 500 levels deep, gets an `error` instead of a view, as in
+REA. Duplicate keys keep their last value before the depth check. Text that is not one JSON
 document, such as JSON Lines, stays text. Format detection follows REA's
 rules. Files larger than 64 MiB get an `error` instead of a view
 and are not read. XML is read with Python's `expat` twice: with namespace

src/cli/coreBinaryCommands.ts

@@ -290,7 +290,7 @@ const registerXrefsCommand = (
   runDirectAnalysis: DirectAnalysis["runDirectAnalysis"],
 ): void => {
   cli.command(CLI_COMMANDS.xrefs, {
-    description: `List bounded references to an analyzed address. ${namedAddressGuidance} ${equalSelectorGuidance}`,
+    description: `List bounded, untyped references to an analyzed address. For typed incoming references, use inspect-native-instruction at the target address where supported. ${namedAddressGuidance} ${equalSelectorGuidance}`,
     args: z.object({
       path: localPathStringSchema.describe("App or program path"),
       address: z

src/cli/coreNativeCommands.ts

@@ -312,7 +312,7 @@ export const registerCoreNativeCommands = (
     cli.command(command, {
       description:
         operation === "inspect_native_instruction"
-          ? "Inspect one native instruction with decoded operand facts"
+          ? "Inspect an exact code or data address for decoded instructions and typed incoming references where supported"
           : "Resolve one static native call site",
       args: z.object({
         path: localPathStringSchema.describe(

src/domain/desktop/appExportPython.ts

@@ -1,3 +1,4 @@
+import { PYTHON_JSON_READER } from "./appExportPythonJson.js";
 import { PYTHON_XML_READER } from "./appExportPythonXml.js";
 import { PYTHON_ZIP_HELPERS } from "./appExportPythonZip.js";
 
@@ -12,6 +13,7 @@ export const PYTHON_READY_CHECK = `
 
 export const PYTHON_IMPORTS = `from __future__ import annotations
 
+from array import array
 import contextlib
 import copy
 import hashlib
@@ -57,11 +59,6 @@ MAX_PARSED_BYTES = 4 * 1024 * 1024
 PARSED_TOO_LARGE = "larger than the 4 MiB limit for JSON and key file views"
 MAX_JSON_VIEW_DEPTH = 500
 JSON_TOO_DEEP = f"nested deeper than the {MAX_JSON_VIEW_DEPTH} levels a JSON view keeps"
-#: A JSON token after any whitespace, by group: an opening, a closing, a comma, a colon, a string's quote, or a number
-#: or literal. Strings are read by json's scanner, since a pattern repeating per escape holds memory for each.
-JSON_TOKEN = re.compile(r'[ \t\n\r]*(?:([\[{])|([\]}])|(,)|(:)|(")|(-?(?:0|[1-9][0-9]*)(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?'
-                        r"|true|false|null))")
-JSON_SPACE = re.compile(r"[ \t\n\r]*")
 
 
 def _respelled(text: str, home: Path) -> str:
@@ -254,143 +251,7 @@ def _keyfile(text: str) -> dict:
 
 ${PYTHON_XML_READER}
 
-def _not_json(constant: str):
-    raise ValueError(f"{constant} is not JSON")
-
-
-class _Inexact(Exception):
-    """A JSON number that REA's state view refuses, since reading it would change it."""
-
-
-def _digits(text: str) -> str:
-    return re.split(r"[eE]", text.lstrip("-"))[0].replace(".", "").strip("0") or "0"
-
-
-def _js_string(value: float) -> str:
-    """How JavaScript's String() writes a finite double: an integer below 1e21 in full, any other in shortest form."""
-    return str(int(value)) if value.is_integer() and abs(value) < 1e21 else repr(value)
-
-
-def _safe_number(text: str) -> bool:
-    """lossless-json's isSafeNumber: an integer spelling within 2^53, or a float spelling that keeps its digits."""
-    if re.fullmatch(r"-?[0-9]+", text):
-        return len(text.lstrip("-")) <= 16 and abs(int(text)) <= MAX_SAFE_INTEGER
-    value = float(text)
-    if not math.isfinite(value):
-        return False
-    written = _js_string(value)
-    return written == text or _digits(written) == _digits(text)
-
-
-def _exact_number(text: str):
-    """A JSON number read only when reading it changes nothing, as REA's state view rules: its spelling and its
-    written-back form both safe, and not -0."""
-    value = float(text)
-    if (not _safe_number(text) or not math.isfinite(value) or not _safe_number(_js_string(value))
-            or (value == 0 and math.copysign(1, value) < 0)):
-        raise _Inexact(text)
-    return int(text) if re.fullmatch(r"-?[0-9]+", text) else value
-
-
-_INEXACT = object()
-_LEVEL_END = object()
-
-
-def _number_or_mark(spelling: str):
-    """A JSON number read exactly, or a mark for one REA's state view refuses."""
-    try:
-        return _exact_number(spelling)
-    except _Inexact:
-        return _INEXACT
-
-
-def _holds_inexact(value) -> bool:
-    """Whether a parsed JSON value still holds a marked number once duplicate keys kept their last value; one
-    iterator per nesting level, so no child list is copied."""
-    levels = [iter((value,))]
-    while levels:
-        item = next(levels[-1], _LEVEL_END)
-        if item is _LEVEL_END:
-            levels.pop()
-        elif item is _INEXACT:
-            return True
-        elif isinstance(item, dict):
-            levels.append(iter(item.values()))
-        elif isinstance(item, list):
-            levels.append(iter(item))
-    return False
-
-
-def _deeper_than(root, limit: int) -> bool:
-    """Whether a parsed JSON value nests deeper than a limit, as REA checks it: a value's depth is the number of
-    iterators open above it, one per nesting level, so no child list is copied."""
-    levels = [iter((root,))]
-    while levels:
-        item = next(levels[-1], _LEVEL_END)
-        if item is _LEVEL_END:
-            levels.pop()
-        elif len(levels) - 1 > limit:
-            return True
-        elif isinstance(item, dict):
-            levels.append(iter(item.values()))
-        elif isinstance(item, list):
-            levels.append(iter(item))
-    return False
-
-
-def _is_json(text: str) -> bool:
-    """Whether text is one JSON value as REA's state view reads it, checked a token at a time without building it or
-    recursing: it holds a byte per open container and one string at a time, so text too deep for Python's parser or
-    too large to parse into a view is still told apart from other text."""
-    containers, expect, empty, at = bytearray(), "value", False, 0
-    while True:
-        token = JSON_TOKEN.match(text, at)
-        if token is None:
-            break
-        kind, at = token.lastindex, token.end()
-        if kind == 5:
-            try:
-                at = json.decoder.scanstring(text, at)[1]
-            except ValueError:
-                return False
-        if kind == 1 and expect == "value":
-            containers.append(ord(text[at - 1]))
-            expect, empty = ("value" if text[at - 1] == "[" else "key"), True
-        # A closing bracket's code is its opening's plus two.
-        elif kind == 2 and (expect == "after" or empty) and containers and containers[-1] == ord(text[at - 1]) - 2:
-            containers.pop()
-            expect, empty = "after", False
-        elif kind == 3 and expect == "after" and containers:
-            expect = "value" if containers[-1] == ord("[") else "key"
-        elif kind == 4 and expect == "colon":
-            expect = "value"
-        elif kind >= 5 and (expect == "value" or (kind == 5 and expect == "key")):
-            expect, empty = ("colon" if expect == "key" else "after"), False
-        else:
-            return False
-    return expect == "after" and not containers and JSON_SPACE.fullmatch(text, at) is not None
-
-
-def _json_view(text: str, size: int):
-    """A JSON text's format and view, or why it has none, as REA reads it; None when it is not JSON. Text over the
-    parsed-view limit, or nested past Python's recursion limit, is told apart without building its value."""
-    if size > MAX_PARSED_BYTES:
-        return {"format": "json", "view": None, "error": PARSED_TOO_LARGE} if _is_json(text) else None
-    # The whole text must parse, and duplicate keys settle, before an inexact number makes it JSON with an error.
-    try:
-        view = json.loads(text, parse_constant=_not_json, parse_float=_number_or_mark, parse_int=_number_or_mark)
-    except RecursionError:
-        # Nesting too deep for Python to parse is far deeper than REA's view keeps, once the rest of it is JSON too.
-        return {"format": "json", "view": None, "error": JSON_TOO_DEEP} if _is_json(text) else None
-    except ValueError:
-        return None
-    if _holds_inexact(view):
-        return {"format": "json", "view": None,
-                "error": "a number in it cannot be read exactly, such as an integer above 2^53"}
-    if _deeper_than(view, MAX_JSON_VIEW_DEPTH):
-        return {"format": "json", "view": None, "error": JSON_TOO_DEEP}
-    return {"format": "json", "view": view, "truncated": False}
-
+${PYTHON_JSON_READER}
 
 def _text_view(name: str, text: str, size: int) -> dict:
     """The format REA's state view detects for decoded text of size bytes, and its view; a JSON or key file over the

src/domain/desktop/appExportPythonJson.ts

@@ -0,0 +1,231 @@
+/** JSON parsing and bounded retained-view checks for exported desktop environments. */
+export const PYTHON_JSON_READER = String.raw`
+#: A JSON token after any whitespace, by group: an opening, a closing, a comma, a colon, a string's quote, or a number
+#: or literal. Strings are read by json's scanner, since a pattern repeating per escape holds memory for each.
+JSON_TOKEN = re.compile(r'[ \t\n\r]*(?:([\[{])|([\]}])|(,)|(:)|(")|(-?(?:0|[1-9][0-9]*)(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?'
+                        r"|true|false|null))")
+JSON_SPACE = re.compile(r"[ \t\n\r]*")
+
+
+class _Inexact(Exception):
+    """A JSON number that REA's state view refuses, since reading it would change it."""
+
+
+def _digits(text: str) -> str:
+    return re.split(r"[eE]", text.lstrip("-"))[0].replace(".", "").strip("0") or "0"
+
+
+def _js_string(value: float) -> str:
+    """How JavaScript's String() writes a finite double: an integer below 1e21 in full, any other in shortest form."""
+    return str(int(value)) if value.is_integer() and abs(value) < 1e21 else repr(value)
+
+
+def _safe_number(text: str) -> bool:
+    """lossless-json's isSafeNumber: an integer spelling within 2^53, or a float spelling that keeps its digits."""
+    if re.fullmatch(r"-?[0-9]+", text):
+        return len(text.lstrip("-")) <= 16 and abs(int(text)) <= MAX_SAFE_INTEGER
+    value = float(text)
+    if not math.isfinite(value):
+        return False
+    written = _js_string(value)
+    return written == text or _digits(written) == _digits(text)
+
+
+def _exact_number(text: str):
+    """A JSON number read only when reading it changes nothing, as REA's state view rules: its spelling and its
+    written-back form both safe, and not -0."""
+    value = float(text)
+    if (not _safe_number(text) or not math.isfinite(value) or not _safe_number(_js_string(value))
+            or (value == 0 and math.copysign(1, value) < 0)):
+        raise _Inexact(text)
+    return int(text) if re.fullmatch(r"-?[0-9]+", text) else value
+
+
+_INEXACT = object()
+_DEEP = object()
+_DEEP_INEXACT = object()
+_LEVEL_END = object()
+_INVALID_JSON = object()
+JSON_ATOMS = {"true": True, "false": False, "null": None}
+
+
+def _number_or_mark(spelling: str):
+    """A JSON number read exactly, or a mark for one REA's state view refuses."""
+    try:
+        return _exact_number(spelling)
+    except _Inexact:
+        return _INEXACT
+
+
+def _holds_inexact(value) -> bool:
+    """Whether a parsed JSON value still holds a marked number once duplicate keys kept their last value; one
+    iterator per nesting level, so no child list is copied."""
+    levels = [iter((value,))]
+    while levels:
+        item = next(levels[-1], _LEVEL_END)
+        if item is _LEVEL_END:
+            levels.pop()
+        elif item is _INEXACT or item is _DEEP_INEXACT:
+            return True
+        elif isinstance(item, dict):
+            levels.append(iter(item.values()))
+        elif isinstance(item, list):
+            levels.append(iter(item))
+    return False
+
+
+def _deeper_than(root, limit: int) -> bool:
+    """Whether a parsed JSON value nests deeper than a limit, as REA checks it: a value's depth is the number of
+    iterators open above it, one per nesting level, so no child list is copied."""
+    levels = [iter((root,))]
+    while levels:
+        item = next(levels[-1], _LEVEL_END)
+        if item is _LEVEL_END:
+            levels.pop()
+        elif item is _DEEP or item is _DEEP_INEXACT:
+            return True
+        elif len(levels) - 1 > limit:
+            return True
+        elif isinstance(item, dict):
+            levels.append(iter(item.values()))
+        elif isinstance(item, list):
+            levels.append(iter(item))
+    return False
+
+
+def _read_json(text: str, build: bool = True):
+    """One JSON value, or _INVALID_JSON, read without recursion so duplicate keys settle before depth is checked.
+    Deep containers are summarized rather than built; exact-number marks still follow last-key-wins semantics.
+    With build=False, only syntax is checked: one byte per open container and one decoded string at a time."""
+    containers, expect, empty, at = bytearray(), "value", False, 0
+    values, keys, root = [], [], _INVALID_JSON
+    deep_bad, deep_key_at, bad_keys = bytearray(), array("I"), {}
+
+    def keep(value) -> None:
+        nonlocal root
+        if not values:
+            root = value
+        elif containers[-1] == ord("["):
+            values[-1].append(value)
+        else:
+            values[-1][keys[-1]] = value
+
+    def record_deep(bad: bool) -> None:
+        """Summarize a finished child; keep only object keys with live inexact values."""
+        depth = len(deep_bad) - 1
+        if containers[-1] == ord("["):
+            deep_bad[-1] |= 2 | bad
+            return
+        marked = bad_keys.get(depth)
+        if bad or marked is not None:
+            key, _ = json.decoder.scanstring(text, deep_key_at[-1])
+            if bad:
+                if marked is None:
+                    marked = key
+                elif isinstance(marked, str):
+                    if marked != key:
+                        marked = {marked, key}
+                else:
+                    marked.add(key)
+            else:
+                if isinstance(marked, str):
+                    if marked == key:
+                        marked = None
+                else:
+                    marked.discard(key)
+                    if len(marked) == 1:
+                        marked = next(iter(marked))
+            if marked is None:
+                bad_keys.pop(depth, None)
+            else:
+                bad_keys[depth] = marked
+            deep_bad[-1] = 2 | (marked is not None)
+        else:
+            deep_bad[-1] |= 2
+
+    while True:
+        token = JSON_TOKEN.match(text, at)
+        if token is None:
+            break
+        kind, at = token.lastindex, token.end()
+        if kind == 5:
+            string_at = at
+            try:
+                value, at = json.decoder.scanstring(text, at)
+            except ValueError:
+                return _INVALID_JSON
+        if kind == 1 and expect == "value":
+            if build:
+                if deep_bad or len(containers) >= MAX_JSON_VIEW_DEPTH:
+                    deep_bad.append(0)
+                    deep_key_at.append(0)
+                else:
+                    value = [] if text[at - 1] == "[" else {}
+                    keep(value)
+                    values.append(value)
+                    keys.append(None)
+            containers.append(ord(text[at - 1]))
+            expect, empty = ("value" if text[at - 1] == "[" else "key"), True
+        # A closing bracket's code is its opening's plus two.
+        elif kind == 2 and (expect == "after" or empty) and containers and containers[-1] == ord(text[at - 1]) - 2:
+            opening = containers.pop()
+            if build:
+                if deep_bad:
+                    state = deep_bad.pop()
+                    bad = bool(state & 1)
+                    deep_key_at.pop()
+                    bad_keys.pop(len(deep_bad), None)
+                    if deep_bad:
+                        record_deep(bad)
+                    else:
+                        keep((_DEEP_INEXACT if bad else _DEEP) if state & 2 else ([] if opening == ord("[") else {}))
+                else:
+                    values.pop()
+                    keys.pop()
+            expect, empty = "after", False
+        elif kind == 3 and expect == "after" and containers:
+            expect = "value" if containers[-1] == ord("[") else "key"
+        elif kind == 4 and expect == "colon":
+            expect = "value"
+        elif kind >= 5 and (expect == "value" or (kind == 5 and expect == "key")):
+            if build:
+                if expect == "key":
+                    if deep_bad:
+                        deep_key_at[-1] = string_at
+                    else:
+                        keys[-1] = value
+                else:
+                    if kind == 6:
+                        value = JSON_ATOMS.get(token[6], _INVALID_JSON)
+                        if value is _INVALID_JSON:
+                            value = _number_or_mark(token[6])
+                    if deep_bad:
+                        record_deep(value is _INEXACT)
+                    else:
+                        keep(value)
+            expect, empty = ("colon" if expect == "key" else "after"), False
+        else:
+            return _INVALID_JSON
+    if expect != "after" or containers or JSON_SPACE.fullmatch(text, at) is None:
+        return _INVALID_JSON
+    return root if build else True
+
+
+def _json_view(text: str, size: int):
+    """A JSON text's format and view, or why it has none, as REA reads it; None when it is not JSON. Text over the
+    parsed-view limit is told apart without building its value."""
+    if size > MAX_PARSED_BYTES:
+        valid = _read_json(text, build=False) is not _INVALID_JSON
+        return {"format": "json", "view": None, "error": PARSED_TOO_LARGE} if valid else None
+    # The whole text must parse, and duplicate keys settle, before an inexact number makes it JSON with an error.
+    view = _read_json(text)
+    if view is _INVALID_JSON:
+        return None
+    if _holds_inexact(view):
+        return {"format": "json", "view": None,
+                "error": "a number in it cannot be read exactly, such as an integer above 2^53"}
+    if _deeper_than(view, MAX_JSON_VIEW_DEPTH):
+        return {"format": "json", "view": None, "error": JSON_TOO_DEEP}
+    return {"format": "json", "view": view, "truncated": False}
+
+`;

tests/boundary/cli/cliHelpDefaultAnnotations.test.ts

@@ -55,10 +55,7 @@ const singleDefaultOptions: readonly {
   { command: "inspect-signal-decoders", options: ["--offset"] },
 ];
 
-const optionLine = (
-  help: string,
-  option: string,
-): string | undefined => {
+const optionLine = (help: string, option: string): string | undefined => {
   const line = help
     .split(/\r?\n/u)
     .find((candidate) => candidate.trimStart().startsWith(`${option} `));
@@ -80,7 +77,9 @@ describe("CLI help default annotations", () => {
         }
         const statements = line.match(/default/giu)?.length ?? 0;
         if (statements !== 1)
-          repeated.push(`${command} ${option}: ${statements} default statements`);
+          repeated.push(
+            `${command} ${option}: ${statements} default statements`,
+          );
       }
     }
     expect(repeated).toEqual([]);

tests/boundary/providers/desktopExportJsonDepth.test.ts

@@ -0,0 +1,205 @@
+import { execFileSync } from "node:child_process";
+import { writeFile } from "node:fs/promises";
+import { join } from "node:path";
+
+import { expect, it } from "vitest";
+
+import {
+  PYTHON_HELPERS,
+  PYTHON_IMPORTS,
+} from "../../../src/domain/desktop/appExportPython.js";
+import {
+  detectStateFormat,
+  textualView,
+} from "../../../src/domain/desktop/stateFormats.js";
+import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
+
+const arrays = "[".repeat(1500) + "1" + "]".repeat(1500);
+const objects = '{"a":'.repeat(1500) + "1" + "}".repeat(1500);
+const cases = [
+  ["discarded arrays", `{"value":${arrays},"value":"done"}`, true],
+  ["discarded objects", `{"value":${objects},"value":"done"}`, true],
+  ["escaped duplicate key", `{"val\\u0075e":${arrays},"value":"done"}`, true],
+  ["retained deep value", `{"value":${arrays}}`, false],
+  [
+    "retained deep inexact number",
+    `{"value":${"[".repeat(600)}9007199254740993${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep overwritten inexact number",
+    `{"value":${"[".repeat(600)}{"x":9007199254740993,"x":1}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep empty-key overwrite",
+    `{"value":${"[".repeat(600)}{"":9007199254740993,"":1}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep multiple inexact keys with one overwritten",
+    `{"value":${"[".repeat(600)}{"a":9007199254740993,"b":9007199254740993,"a":1}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep multiple inexact keys all overwritten",
+    `{"value":${"[".repeat(600)}{"a":9007199254740993,"b":9007199254740993,"a":1,"b":2}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep inexact key replaced by inexact",
+    `{"value":${"[".repeat(600)}{"a":9007199254740993,"a":9007199254740995}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "deep escaped duplicate overwritten",
+    `{"value":${"[".repeat(600)}{"\\u0061":9007199254740993,"a":1}${"]".repeat(600)}}`,
+    false,
+  ],
+  [
+    "discarded deep inexact subtree",
+    `{"value":${"[".repeat(600)}9007199254740993${"]".repeat(600)},"value":"done"}`,
+    true,
+  ],
+  ["last admitted depth", "[".repeat(500) + "1" + "]".repeat(500), true],
+  ["empty container at limit", "[".repeat(501) + "]".repeat(501), true],
+  ["empty container over limit", "[".repeat(502) + "]".repeat(502), false],
+  ["trailing comma", `{"value":${arrays},"value":"done",}`, false],
+  ["missing value", `{"value":${arrays},"value":}`, false],
+  ["wrong closing bracket", `{"value":${arrays},"value":"done"]`, false],
+] as const;
+
+it.each(cases)("reads JSON with %s", async (_name, text, readable) => {
+  const root = await createTestTempDirectory("desktop-json-depth-");
+  const script = join(root, "read.py");
+  const imports = PYTHON_IMPORTS.split("\n")
+    .filter((line) => !line.includes("agentenv_protocol"))
+    .join("\n");
+  await writeFile(
+    script,
+    `${imports}${PYTHON_HELPERS}
+text = json.load(sys.stdin)
+print(json.dumps(_text_view("state.json", text, len(text.encode("utf-8")))))
+`,
+  );
+  const output = JSON.parse(
+    execFileSync(
+      process.platform === "win32" ? "python" : "python3",
+      ["-I", "-B", "-X", "utf8", script],
+      { input: JSON.stringify(text), encoding: "utf8" },
+    ),
+  ) as { format: string; view: unknown; error?: string };
+  const bytes = Buffer.from(text);
+  const format = detectStateFormat("state.json", bytes);
+  if (format !== "json" && format !== "text")
+    throw new Error(`Unexpected native format ${format}`);
+  const native = textualView(format, bytes);
+  expect(format === "json" && native.ok).toBe(readable);
+  expect(output.format).toBe(format);
+  if (native.ok) {
+    expect(output.error).toBeUndefined();
+    // Compare JSON values on their wire form, independent of object prototypes.
+    expect(JSON.stringify(output.view)).toBe(JSON.stringify(native.value));
+    if (
+      readable &&
+      (_name.startsWith("discarded") || _name === "escaped duplicate key")
+    )
+      expect(output.view).toEqual({ value: "done" });
+  } else {
+    expect(output.view).toBeNull();
+    expect(output.error).toBe(native.error);
+  }
+});
+
+it("bounds construction before refusing retained excessive JSON depth", async () => {
+  const root = await createTestTempDirectory("desktop-json-construction-");
+  const script = join(root, "bounded.py");
+  const imports = PYTHON_IMPORTS.split("\n")
+    .filter((line) => !line.includes("agentenv_protocol"))
+    .join("\n");
+  await writeFile(
+    script,
+    `${imports}${PYTHON_HELPERS}
+import tracemalloc
+text = "[" * 20_000 + "0" + "]" * 20_000
+recursion_limit = sys.getrecursionlimit()
+tracemalloc.start()
+entry = _json_view(text, len(text))
+peak = tracemalloc.get_traced_memory()[1]
+tracemalloc.stop()
+print(json.dumps({"entry": entry, "peak": peak, "recursion_unchanged": sys.getrecursionlimit() == recursion_limit}))
+`,
+  );
+  const output = JSON.parse(
+    execFileSync(
+      process.platform === "win32" ? "python" : "python3",
+      ["-I", "-B", "-X", "utf8", script],
+      { encoding: "utf8" },
+    ),
+  ) as { entry: unknown; peak: number; recursion_unchanged: boolean };
+  expect(output.entry).toEqual({
+    format: "json",
+    view: null,
+    error: "nested deeper than the 500 levels a JSON view keeps",
+  });
+  expect(output.recursion_unchanged).toBe(true);
+  // Python heap only, excluding source construction and interpreter/OS memory.
+  // A value retained only to refuse it must not allocate every input container.
+  expect(output.peak).toBeLessThan(1024 * 1024);
+});
+
+it("bounds allocations when a very deep value is overwritten", async () => {
+  const root = await createTestTempDirectory("desktop-json-memory-");
+  const script = join(root, "read.py");
+  const imports = PYTHON_IMPORTS.split("\n")
+    .filter((line) => !line.includes("agentenv_protocol"))
+    .join("\n");
+  await writeFile(
+    script,
+    `${imports}\nimport tracemalloc\n${PYTHON_HELPERS}
+text = '{"value":' + '[' * 200000 + '1' + ']' * 200000 + ',"value":"done"}'
+tracemalloc.start()
+result = _json_view(text, len(text))
+_, peak = tracemalloc.get_traced_memory()
+print(json.dumps({"view": result["view"], "peak": peak}))
+`,
+  );
+  const measured = JSON.parse(
+    execFileSync(
+      process.platform === "win32" ? "python" : "python3",
+      ["-I", "-B", script],
+      { encoding: "utf8", timeout: 30000 },
+    ),
+  ) as { view: unknown; peak: number };
+  expect(measured.view).toEqual({ value: "done" });
+  expect(measured.peak).toBeLessThan(8 * 1024 * 1024);
+}, 40000);
+
+it("bounds a wide container already beyond the retained view depth", async () => {
+  const root = await createTestTempDirectory("desktop-json-wide-depth-");
+  const script = join(root, "read.py");
+  const imports = PYTHON_IMPORTS.split("\n")
+    .filter((line) => !line.includes("agentenv_protocol"))
+    .join("\n");
+  await writeFile(
+    script,
+    `${imports}\nimport tracemalloc\n${PYTHON_HELPERS}
+text = '[' * 501 + ','.join(['"abc"'] * 600000) + ']' * 501
+tracemalloc.start()
+result = _json_view(text, len(text))
+_, peak = tracemalloc.get_traced_memory()
+print(json.dumps({"error": result.get("error"), "peak": peak}))
+`,
+  );
+  const measured = JSON.parse(
+    execFileSync(
+      process.platform === "win32" ? "python" : "python3",
+      ["-I", "-B", script],
+      { encoding: "utf8", timeout: 30000 },
+    ),
+  ) as { error: string; peak: number };
+  expect(measured.error).toBe(
+    "nested deeper than the 500 levels a JSON view keeps",
+  );
+  expect(measured.peak).toBeLessThan(8 * 1024 * 1024);
+}, 40000);

tests/boundary/providers/desktopExportPython.test.ts

@@ -34,7 +34,7 @@ const execPython = (
   try {
     writeFileSync(script, args[codeIndex + 1]!, "utf8");
     return execFileSync(
-      "python3",
+      process.platform === "win32" ? "python" : "python3",
       [
         "-X",
         "utf8",
@@ -375,15 +375,16 @@ it("checks text for JSON the way REA does, token by token, without parsing it",
         "-I",
         "-B",
         "-c",
-        `${imports}${PYTHON_HELPERS}\nprint(json.dumps([_is_json(text) for text in json.load(sys.stdin)]))`,
+        `${imports}${PYTHON_HELPERS}\ntexts = json.load(sys.stdin)\nprint(json.dumps({"syntax": [_read_json(text, build=False) is not _INVALID_JSON for text in texts], "built": [_read_json(text) is not _INVALID_JSON for text in texts]}))`,
       ],
       { input: JSON.stringify(texts), encoding: "utf8" },
     ),
-  ) as boolean[];
+  ) as { syntax: boolean[]; built: boolean[] };
 
   const parsed = texts.map((text) => safeParseJson(text).ok);
   expect(texts.map((text) => isJsonText(text))).toEqual(parsed);
-  expect(python).toEqual(parsed);
+  expect(python.syntax).toEqual(parsed);
+  expect(python.built).toEqual(parsed);
   expect(parsed.filter(Boolean)).toHaveLength(10);
 });
 
@@ -445,9 +446,13 @@ print(json.dumps([_text_view("settings.ini", text, len(text.encode()))["view"]["
   const root = await createTestTempDirectory("rea-keyfile-python-");
   const script = join(root, "fixture.py");
   await writeFile(script, program, "utf8");
-  const output = execFileSync("python3", ["-I", "-B", "-X", "utf8", script], {
-    input: JSON.stringify(inputs),
-    encoding: "utf8",
-  });
+  const output = execFileSync(
+    process.platform === "win32" ? "python" : "python3",
+    ["-I", "-B", "-X", "utf8", script],
+    {
+      input: JSON.stringify(inputs),
+      encoding: "utf8",
+    },
+  );
   expect(JSON.parse(output)).toEqual(inputs.map(keyfileView));
 });