[captive_portal] Re-apply json_escape move lost in release merge (#17906)

esphome/components/captive_portal/captive_portal.cpp

@@ -6,7 +6,6 @@
 #include "esphome/core/string_ref.h"
 #include "esphome/components/wifi/wifi_component.h"
 #include "captive_index.h"
-#include "json_escape.h"
 
 namespace esphome::captive_portal {
 

esphome/components/captive_portal/json_escape.h

@@ -1,85 +0,0 @@
-#pragma once
-#include <cstddef>
-#include <cstdint>
-#include <span>
-
-#include "esphome/core/helpers.h"
-#include "esphome/core/string_ref.h"
-
-namespace esphome::captive_portal {
-
-/// Largest number of output bytes a single input byte can expand to (a \u00XX sequence).
-static constexpr size_t JSON_ESCAPE_MAX_EXPANSION = 6;
-
-/// Copy value into buf, escaping the characters that cannot appear raw inside a JSON string literal.
-///
-/// Escapes " and \ along with the control characters below 0x20, using the short forms where JSON defines one and
-/// \u00XX otherwise. Bytes >= 0x20 are copied verbatim, so text containing valid UTF-8 survives intact. The result is
-/// always null terminated; anything that would not fit is dropped rather than written partially. Returns buf so the
-/// call can be used directly as an argument.
-///
-/// To size buf so that no input is ever dropped, allow JSON_ESCAPE_MAX_EXPANSION bytes per input byte plus one for
-/// the null terminator.
-inline const char *json_escape_into_buffer(std::span<char> buf, StringRef value) {
-  if (buf.empty())
-    return "";
-  // Reserve one byte for the null terminator.
-  const size_t limit = buf.size() - 1;
-  size_t pos = 0;
-  for (char ch : value) {
-    auto c = static_cast<unsigned char>(ch);
-    // Every short form is a backslash followed by a single character, so only that character is needed here. Keeping
-    // it a char rather than a string avoids putting the sequences in read only data, which is RAM on the ESP8266.
-    char escape = '\0';
-    switch (c) {
-      case '"':
-        escape = '"';
-        break;
-      case '\\':
-        escape = '\\';
-        break;
-      case '\n':
-        escape = 'n';
-        break;
-      case '\r':
-        escape = 'r';
-        break;
-      case '\t':
-        escape = 't';
-        break;
-      case '\b':
-        escape = 'b';
-        break;
-      case '\f':
-        escape = 'f';
-        break;
-      default:
-        break;
-    }
-    if (escape != '\0') {
-      if (pos + 2 > limit)
-        break;
-      buf[pos++] = '\\';
-      buf[pos++] = escape;
-    } else if (c < 0x20) {
-      // Remaining control characters have no short form and must be written as \u00XX. The value is below 0x20, so
-      // the two high hex digits are always zero.
-      if (pos + JSON_ESCAPE_MAX_EXPANSION > limit)
-        break;
-      buf[pos++] = '\\';
-      buf[pos++] = 'u';
-      buf[pos++] = '0';
-      buf[pos++] = '0';
-      buf[pos++] = format_hex_char(static_cast<uint8_t>(c >> 4));
-      buf[pos++] = format_hex_char(static_cast<uint8_t>(c & 0x0F));
-    } else {
-      if (pos + 1 > limit)
-        break;
-      buf[pos++] = static_cast<char>(c);
-    }
-  }
-  buf[pos] = '\0';
-  return buf.data();
-}
-
-}  // namespace esphome::captive_portal

tests/components/captive_portal/__init__.py

@@ -1,23 +0,0 @@
-"""Test-manifest overrides for the captive_portal C++ unit tests.
-
-``json_escape`` lives in a standalone, dependency-free header
-(``esphome/components/captive_portal/json_escape.h``). The rest of the
-captive_portal component and its auto-loaded dependencies (``web_server_base``,
-``ota.web_server``) do not build for the ``host`` platform that the C++ unit
-test harness targets. Strip those away and replace the real schema -- which is
-restricted to non-host platforms via ``cv.only_on`` and requires a
-``web_server_base`` instance via ``use_id`` -- with an empty one so the host
-test config validates. ``to_code`` stays suppressed (the default), so
-``USE_CAPTIVE_PORTAL`` is never defined and ``captive_portal.cpp`` compiles to an
-empty translation unit; only ``json_escape.h`` is exercised by the test.
-"""
-
-import esphome.config_validation as cv
-from tests.testing_helpers import ComponentManifestOverride
-
-
-def override_manifest(manifest: ComponentManifestOverride) -> None:
-    manifest.auto_load = []
-    manifest.dependencies = []
-    manifest.config_schema = cv.Schema({})
-    manifest.final_validate_schema = None

tests/components/captive_portal/json_escape_test.cpp

@@ -1,107 +0,0 @@
-#include <gtest/gtest.h>
-
-#include <string>
-
-#include "esphome/components/captive_portal/json_escape.h"
-
-namespace esphome::captive_portal::testing {
-
-namespace {
-
-// Large enough that none of the inputs below are ever dropped.
-constexpr size_t TEST_BUFFER_SIZE = 64 * JSON_ESCAPE_MAX_EXPANSION + 1;
-
-// Escape into a stack buffer and return the result as a string so the expectations stay readable.
-std::string escape(const std::string &value) {
-  char buf[TEST_BUFFER_SIZE];
-  return json_escape_into_buffer(buf, StringRef(value.c_str(), value.size()));
-}
-
-}  // namespace
-
-// Plain ASCII with no special characters is passed through unchanged.
-TEST(CaptivePortalJsonEscape, PlainStringUnchanged) {
-  EXPECT_EQ(escape("MyNetwork"), "MyNetwork");
-  EXPECT_EQ(escape(""), "");
-}
-
-// A double quote is escaped so it does not terminate the surrounding JSON string.
-TEST(CaptivePortalJsonEscape, EscapesDoubleQuote) {
-  EXPECT_EQ(escape("a\"b"), "a\\\"b");
-  // A double quote followed by other characters stays inside the JSON string.
-  EXPECT_EQ(escape("\">end"), "\\\">end");
-}
-
-// A backslash is doubled so it does not start an escape sequence in the output.
-TEST(CaptivePortalJsonEscape, EscapesBackslash) {
-  EXPECT_EQ(escape("a\\b"), "a\\\\b");
-  // A trailing backslash must not escape the closing quote of the JSON string.
-  EXPECT_EQ(escape("net\\"), "net\\\\");
-}
-
-// The control characters with short JSON forms use those forms.
-TEST(CaptivePortalJsonEscape, EscapesShortFormControls) {
-  EXPECT_EQ(escape("\n"), "\\n");
-  EXPECT_EQ(escape("\r"), "\\r");
-  EXPECT_EQ(escape("\t"), "\\t");
-  EXPECT_EQ(escape("\b"), "\\b");
-  EXPECT_EQ(escape("\f"), "\\f");
-}
-
-// Other control characters (< 0x20) without a short form become \u00XX with lowercase hex.
-TEST(CaptivePortalJsonEscape, EscapesOtherControlsAsUnicode) {
-  EXPECT_EQ(escape(std::string("\x00", 1)), "\\u0000");
-  EXPECT_EQ(escape("\x01"), "\\u0001");
-  EXPECT_EQ(escape("\x10"), "\\u0010");
-  EXPECT_EQ(escape("\x1f"), "\\u001f");
-  // 0x7f (DEL) is >= 0x20, so it is NOT escaped by this helper.
-  EXPECT_EQ(escape("\x7f"), "\x7f");
-}
-
-// Bytes >= 0x20, including multi-byte UTF-8 sequences, are passed through verbatim.
-TEST(CaptivePortalJsonEscape, PassesThroughUtf8) {
-  // "café" in UTF-8 (é == 0xC3 0xA9).
-  EXPECT_EQ(escape("caf\xc3\xa9"), "caf\xc3\xa9");
-  // Emoji (📶, 4-byte UTF-8) survives unchanged.
-  EXPECT_EQ(escape("\xf0\x9f\x93\xb6"), "\xf0\x9f\x93\xb6");
-}
-
-// A mix of special and normal characters is escaped in place without disturbing the rest.
-TEST(CaptivePortalJsonEscape, MixedContent) { EXPECT_EQ(escape("a\"b\\c\nd"), "a\\\"b\\\\c\\nd"); }
-
-// A buffer sized at JSON_ESCAPE_MAX_EXPANSION bytes per input byte holds the worst case exactly.
-TEST(CaptivePortalJsonEscape, WorstCaseInputFitsExactly) {
-  constexpr size_t input_len = 8;
-  char buf[input_len * JSON_ESCAPE_MAX_EXPANSION + 1];
-  const std::string input(input_len, '\x01');
-  std::string expected;
-  for (size_t i = 0; i < input_len; i++)
-    expected += "\\u0001";
-  EXPECT_EQ(json_escape_into_buffer(buf, StringRef(input.c_str(), input.size())), expected);
-}
-
-// An escape sequence that would not fit is dropped whole rather than written partially, and the result stays null
-// terminated.
-TEST(CaptivePortalJsonEscape, DropsEscapeThatWouldNotFit) {
-  // Room for one \u00XX sequence plus the null terminator, but two are requested.
-  char buf[JSON_ESCAPE_MAX_EXPANSION + 1];
-  const std::string input(2, '\x01');
-  const std::string result = json_escape_into_buffer(buf, StringRef(input.c_str(), input.size()));
-  EXPECT_EQ(result, "\\u0001");
-  EXPECT_EQ(buf[JSON_ESCAPE_MAX_EXPANSION], '\0');
-}
-
-// Plain characters are truncated at the buffer size, leaving room for the null terminator.
-TEST(CaptivePortalJsonEscape, TruncatesPlainInput) {
-  char buf[5];
-  const std::string input(20, 'a');
-  EXPECT_STREQ(json_escape_into_buffer(buf, StringRef(input.c_str(), input.size())), "aaaa");
-}
-
-// A zero length buffer cannot even hold a null terminator, so an empty string is returned instead of writing.
-TEST(CaptivePortalJsonEscape, EmptyBufferIsSafe) {
-  const std::string input("test");
-  EXPECT_STREQ(json_escape_into_buffer(std::span<char>(), StringRef(input.c_str(), input.size())), "");
-}
-
-}  // namespace esphome::captive_portal::testing