string(JSON): Adds JSON parsing support to the string command

Adds a set of sub commands to the string command for parsing JSON, the
JSON commands are: GET, TYPE, MEMBER, LENGTH, REMOVE, SET, and EQUAL.

Closes: #19501

15 files changed, 382 insertions, 0 deletions

diff --git a/Tests/RunCMake/string/JSON.cmake b/Tests/RunCMake/string/JSON.cmake
new file mode 100644
index 0000000..ab4194d
--- /dev/null
+++ b/Tests/RunCMake/string/JSON.cmake
@@ -0,0 +1,342 @@
+function(assert_strequal actual expected)
+  if(NOT expected STREQUAL actual)
+    message(SEND_ERROR "Output:\n${actual}\nDid not match expected:\n${expected}\n")
+  endif()
+endfunction()
+
+function(assert_strequal_error actual expected error)
+  if(error)
+    message(SEND_ERROR "Unexpected error: ${error}")
+  endif()
+  assert_strequal("${actual}" "${expected}")
+endfunction()
+
+function(assert_json_equal error actual expected)
+  if(error)
+    message(SEND_ERROR "Unexpected error: ${error}")
+  endif()
+  string(JSON eql EQUAL "${actual}" "${expected}")
+  if(NOT eql)
+    message(SEND_ERROR "Expected equality got\n ${actual}\n expected\n${expected}")
+  endif()
+endfunction()
+
+# test EQUAL
+string(JSON result EQUAL
+[=[ {"foo":"bar"} ]=]
+[=[
+{
+"foo": "bar"
+}
+]=])
+if(NOT result)
+  message(SEND_ERROR "Expected ON got ${result}")
+endif()
+
+string(JSON result EQUAL
+[=[ {"foo":"bar"} ]=]
+[=[
+{
+"foo1": "bar"
+}
+]=])
+if(result)
+  message(SEND_ERROR "Expected OFF got ${result}")
+endif()
+
+
+
+set(json1 [=[
+{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null],
+  "types" : {
+    "null" : null,
+    "number" : 5,
+    "string" : "foo",
+    "boolean" : false,
+    "array" : [1,2,3],
+    "object" : {}
+  },
+  "values" : {
+    "null" : null,
+    "number" : 5,
+    "string" : "foo",
+    "false" : false,
+    "true" : true
+  },
+  "special" : {
+    "foo;bar" : "value1",
+    ";" : "value2",
+    "semicolon" : ";",
+    "list" : ["one", "two;three", "four"],
+    "quote" : "\"",
+    "\"" : "quote",
+    "backslash" : "\\",
+    "\\" : "backslash",
+    "slash" : "\/",
+    "\/" : "slash",
+    "newline" : "\n",
+    "\n" : "newline",
+    "return" : "\r",
+    "\r" : "return",
+    "tab" : "\t",
+    "\t" : "tab",
+    "backspace" : "\b",
+    "\b" : "backspace",
+    "formfeed" : "\f",
+    "\f" : "formfeed"
+   }
+}
+]=])
+
+string(JSON result GET "${json1}" foo)
+assert_strequal("${result}" bar)
+string(JSON result GET "${json1}" array 0)
+assert_strequal("${result}" 5)
+string(JSON result GET "${json1}" array 1)
+assert_strequal("${result}" val)
+string(JSON result GET "${json1}" array 2 some)
+assert_strequal("${result}" other)
+
+string(JSON result GET "${json1}" values null)
+assert_strequal("${result}" "")
+string(JSON result GET "${json1}" values number)
+assert_strequal("${result}" 5)
+string(JSON result GET "${json1}" values string)
+assert_strequal("${result}" "foo")
+string(JSON result GET "${json1}" values true)
+assert_strequal("${result}" "ON")
+if(NOT result)
+  message(SEND_ERROR "Output did not match expected: TRUE actual: ${result}")
+endif()
+string(JSON result GET "${json1}" values false)
+assert_strequal("${result}" "OFF")
+if(result)
+  message(SEND_ERROR "Output did not match expected: FALSE actual: ${result}")
+endif()
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" foo)
+assert_strequal_error("${result}" "bar" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" notThere)
+assert_strequal("${result}" "notThere-NOTFOUND")
+assert_strequal("${error}" "member 'notThere' not found")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" 0)
+assert_strequal("${result}" "0-NOTFOUND")
+assert_strequal("${error}" "member '0' not found")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" array 10)
+assert_strequal("${result}" "array-10-NOTFOUND")
+assert_strequal("${error}" "expected an index less then 4 got '10'")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" array 2 some notThere)
+assert_strequal("${result}" "array-2-some-notThere-NOTFOUND")
+assert_strequal("${error}" "invalid path 'array 2 some notThere', need element of OBJECT or ARRAY type to lookup 'notThere' got STRING")
+
+# special chars
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "foo;bar")
+assert_strequal_error("${result}" "value1" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special ";")
+assert_strequal_error("${result}" "value2" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special semicolon)
+assert_strequal_error("${result}" ";" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special list 1)
+assert_strequal_error("${result}" "two;three" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}")
+assert_json_equal("${error}" "${result}" "${json1}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" array)
+assert_json_equal("${error}" "${result}" [=[ [5, "val", {"some": "other"}, null] ]=])
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special quote)
+assert_strequal_error("${result}" "\"" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "\"")
+assert_strequal_error("${result}" "quote" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special backslash)
+assert_strequal_error("${result}" "\\" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "\\")
+assert_strequal_error("${result}" "backslash" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special slash)
+assert_strequal_error("${result}" "/" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "/")
+assert_strequal_error("${result}" "slash" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special newline)
+assert_strequal_error("${result}" "\n" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "\n")
+assert_strequal_error("${result}" "newline" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special return)
+assert_strequal_error("${result}" "\r" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "\r")
+assert_strequal_error("${result}" "return" "${error}")
+
+string(JSON result ERROR_VARIABLE error GET "${json1}" special tab)
+assert_strequal_error("${result}" "\t" "${error}")
+string(JSON result ERROR_VARIABLE error GET "${json1}" special "\t")
+assert_strequal_error("${result}" "tab" "${error}")
+
+file(READ ${CMAKE_CURRENT_LIST_DIR}/json/unicode.json unicode)
+string(JSON char ERROR_VARIABLE error GET "${unicode}" backspace)
+string(JSON result ERROR_VARIABLE error GET "${unicode}" "${char}")
+assert_strequal_error("${result}" "backspace" "${error}")
+
+file(READ ${CMAKE_CURRENT_LIST_DIR}/json/unicode.json unicode)
+string(JSON char ERROR_VARIABLE error GET "${unicode}" backspace)
+string(JSON result ERROR_VARIABLE error GET "${unicode}" "${char}")
+assert_strequal_error("${result}" "backspace" "${error}")
+
+string(JSON char ERROR_VARIABLE error GET "${unicode}" formfeed)
+string(JSON result ERROR_VARIABLE error GET "${unicode}" "${char}")
+assert_strequal_error("${result}" "formfeed" "${error}")
+
+string(JSON char ERROR_VARIABLE error GET "${unicode}" datalinkescape)
+string(JSON result ERROR_VARIABLE error GET "${unicode}" "${char}")
+assert_strequal_error("${result}" "datalinkescape" "${error}")
+
+# Test TYPE
+string(JSON result TYPE "${json1}" types null)
+assert_strequal("${result}" NULL)
+string(JSON result TYPE "${json1}" types number)
+assert_strequal("${result}" NUMBER)
+string(JSON result TYPE "${json1}" types string)
+assert_strequal("${result}" STRING)
+string(JSON result TYPE "${json1}" types boolean)
+assert_strequal("${result}" BOOLEAN)
+string(JSON result TYPE "${json1}" types array)
+assert_strequal("${result}" ARRAY)
+string(JSON result TYPE "${json1}" types object)
+assert_strequal("${result}" OBJECT)
+
+# Test LENGTH
+string(JSON result ERROR_VARIABLE error LENGTH "${json1}")
+assert_strequal("${result}" 5)
+if(error)
+  message(SEND_ERROR "Unexpected error: ${error}")
+endif()
+
+string(JSON result ERROR_VARIABLE error LENGTH "${json1}" array)
+assert_strequal("${result}" 4)
+if(error)
+  message(SEND_ERROR "Unexpected error: ${error}")
+endif()
+
+string(JSON result ERROR_VARIABLE error LENGTH "${json1}" foo)
+assert_strequal("${result}" "foo-NOTFOUND")
+assert_strequal("${error}" "LENGTH needs to be called with an element of type ARRAY or OBJECT, got STRING")
+
+# Test MEMBER
+string(JSON result ERROR_VARIABLE error MEMBER "${json1}" values 2)
+assert_strequal("${result}" "number")
+if(error)
+  message(SEND_ERROR "Unexpected error: ${error}")
+endif()
+
+string(JSON result ERROR_VARIABLE error MEMBER "${json1}" values 100)
+assert_strequal("${result}" "values-100-NOTFOUND")
+assert_strequal("${error}" "expected an index less then 5 got '100'")
+
+# Test length loops
+string(JSON arrayLength ERROR_VARIABLE error LENGTH "${json1}" types array)
+if(error)
+  message(SEND_ERROR "Unexpected error: ${error}")
+endif()
+set(values "")
+math(EXPR arrayLength "${arrayLength}-1")
+foreach(index RANGE ${arrayLength})
+  string(JSON value ERROR_VARIABLE error GET "${json1}" types array ${index})
+  if(error)
+    message(SEND_ERROR "Unexpected error: ${error}")
+  endif()
+  list(APPEND values "${value}")
+endforeach()
+assert_strequal("${values}" "1;2;3")
+
+string(JSON valuesLength ERROR_VARIABLE error LENGTH "${json1}" values)
+if(error)
+  message(SEND_ERROR "Unexpected error: ${error}")
+endif()
+set(values "")
+set(members "")
+math(EXPR valuesLength "${valuesLength}-1")
+foreach(index RANGE ${valuesLength})
+  string(JSON member ERROR_VARIABLE error MEMBER "${json1}" values ${index})
+  if(error)
+    message(SEND_ERROR "Unexpected error: ${error}")
+  endif()
+  string(JSON value ERROR_VARIABLE error GET "${json1}" values ${member})
+  if(error)
+    message(SEND_ERROR "Unexpected error: ${error}")
+  endif()
+
+  list(APPEND members "${member}")
+  list(APPEND values "${value}")
+endforeach()
+assert_strequal("${members}" "false;null;number;string;true")
+assert_strequal("${values}" "OFF;;5;foo;ON")
+
+# Test REMOVE
+set(json2 [=[{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null]
+}]=])
+string(JSON result ERROR_VARIABLE error REMOVE ${json2} foo)
+assert_json_equal("${error}" "${result}"
+[=[{
+  "array" : [5, "val", {"some": "other"}, null]
+}]=])
+
+string(JSON result ERROR_VARIABLE error REMOVE ${json2} array 1)
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [5, {"some": "other"}, null]
+}]=])
+
+string(JSON result ERROR_VARIABLE error REMOVE ${json2} array 100)
+assert_strequal("${result}" "array-100-NOTFOUND")
+assert_strequal("${error}" "expected an index less then 4 got '100'")
+
+# Test SET
+string(JSON result ERROR_VARIABLE error SET ${json2} new 5)
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null],
+  "new" : 5
+}]=])
+
+string(JSON result ERROR_VARIABLE error SET ${json2} new [=[ {"obj" : false} ]=])
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null],
+  "new" : {"obj" : false}
+}]=])
+
+string(JSON result ERROR_VARIABLE error SET ${json2} array 0 6)
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [6, "val", {"some": "other"}, null]
+}]=])
+
+string(JSON result ERROR_VARIABLE error SET ${json2} array 5 [["append"]])
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null, "append"]
+}]=])
+
+string(JSON result ERROR_VARIABLE error SET ${json2} array 100 [["append"]])
+assert_json_equal("${error}" "${result}"
+[=[{
+  "foo" : "bar",
+  "array" : [5, "val", {"some": "other"}, null, "append"]
+}]=])
diff --git a/Tests/RunCMake/string/JSONNoArgs-result.txt b/Tests/RunCMake/string/JSONNoArgs-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoArgs-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/string/JSONNoArgs-stderr.txt b/Tests/RunCMake/string/JSONNoArgs-stderr.txt
new file mode 100644
index 0000000..426735a
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoArgs-stderr.txt
@@ -0,0 +1,4 @@
+CMake Error at JSONNoArgs.cmake:1 \(string\):
+  string sub-command JSON missing out-var argument.
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/string/JSONNoArgs.cmake b/Tests/RunCMake/string/JSONNoArgs.cmake
new file mode 100644
index 0000000..4463fe4
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoArgs.cmake
@@ -0,0 +1 @@
+string(JSON)
diff --git a/Tests/RunCMake/string/JSONNoJson-result.txt b/Tests/RunCMake/string/JSONNoJson-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoJson-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/string/JSONNoJson-stderr.txt b/Tests/RunCMake/string/JSONNoJson-stderr.txt
new file mode 100644
index 0000000..26804df
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoJson-stderr.txt
@@ -0,0 +1,4 @@
+CMake Error at JSONNoJson.cmake:1 \(string\):
+  string sub-command JSON missing json string argument.
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/string/JSONNoJson.cmake b/Tests/RunCMake/string/JSONNoJson.cmake
new file mode 100644
index 0000000..4f819f1
--- /dev/null
+++ b/Tests/RunCMake/string/JSONNoJson.cmake
@@ -0,0 +1 @@
+string(JSON var GET)
diff --git a/Tests/RunCMake/string/JSONOneArg-result.txt b/Tests/RunCMake/string/JSONOneArg-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/string/JSONOneArg-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/string/JSONOneArg-stderr.txt b/Tests/RunCMake/string/JSONOneArg-stderr.txt
new file mode 100644
index 0000000..282139c
--- /dev/null
+++ b/Tests/RunCMake/string/JSONOneArg-stderr.txt
@@ -0,0 +1,4 @@
+CMake Error at JSONOneArg.cmake:1 \(string\):
+  string sub-command JSON missing mode argument.
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/string/JSONOneArg.cmake b/Tests/RunCMake/string/JSONOneArg.cmake
new file mode 100644
index 0000000..143f9ca
--- /dev/null
+++ b/Tests/RunCMake/string/JSONOneArg.cmake
@@ -0,0 +1 @@
+string(JSON var)
diff --git a/Tests/RunCMake/string/JSONWrongMode-result.txt b/Tests/RunCMake/string/JSONWrongMode-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/string/JSONWrongMode-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/string/JSONWrongMode-stderr.txt b/Tests/RunCMake/string/JSONWrongMode-stderr.txt
new file mode 100644
index 0000000..c70991b
--- /dev/null
+++ b/Tests/RunCMake/string/JSONWrongMode-stderr.txt
@@ -0,0 +1,5 @@
+CMake Error at JSONWrongMode.cmake:1 \(string\):
+  string sub-command JSON got an invalid mode 'FOO', expected one of GET,
+  GET_ARRAY, TYPE, MEMBER, MEMBERS, LENGTH, REMOVE, SET, EQUAL.
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/string/JSONWrongMode.cmake b/Tests/RunCMake/string/JSONWrongMode.cmake
new file mode 100644
index 0000000..7301f7a
--- /dev/null
+++ b/Tests/RunCMake/string/JSONWrongMode.cmake
@@ -0,0 +1 @@
+string(JSON var FOO)
diff --git a/Tests/RunCMake/string/RunCMakeTest.cmake b/Tests/RunCMake/string/RunCMakeTest.cmake
index bb7cb17..ff0bb51 100644
--- a/Tests/RunCMake/string/RunCMakeTest.cmake
+++ b/Tests/RunCMake/string/RunCMakeTest.cmake
@@ -1,5 +1,12 @@
 include(RunCMake)
 
+run_cmake(JSON)
+
+run_cmake(JSONNoJson)
+run_cmake(JSONWrongMode)
+run_cmake(JSONOneArg)
+run_cmake(JSONNoArgs)
+
 run_cmake(Append)
 run_cmake(AppendNoArgs)
 
diff --git a/Tests/RunCMake/string/json/unicode.json b/Tests/RunCMake/string/json/unicode.json
new file mode 100644
index 0000000..86fd232
--- /dev/null
+++ b/Tests/RunCMake/string/json/unicode.json
@@ -0,0 +1,8 @@
+{
+    "backspace" : "\b",
+    "\b" : "backspace",
+    "formfeed" : "\f",
+    "\f" : "formfeed" ,
+    "datalinkescape" : "\u0010",
+    "\u0010" : "datalinkescape"
+}