Allow Fail Function to Expand Twice

README.md

@@ -162,7 +162,9 @@ This macro throws a fatal error message formatted from the given `<lines>`.
 
 It formats the message by concatenating all the lines into a single message. If
 one of the lines is a variable, it will be expanded and indented by two spaces
-before being concatenated with the other lines.
+before being concatenated with the other lines. If the expanded variable is
+another variable, it will format both the name and the value of the other
+variable.
 
 #### Example
 

cmake/Assertion.cmake

@@ -75,19 +75,34 @@ endfunction()
 #
 # It formats the message by concatenating all the lines into a single message.
 # If one of the lines is a variable, it will be expanded and indented by two
-# spaces before being concatenated with the other lines.
+# spaces before being concatenated with the other lines. If the expanded
+# variable is another variable, it will format both the name and the value of
+# the other variable.
 macro(fail FIRST_LINE)
-  if(DEFINED "${FIRST_LINE}")
-    set(MESSAGE "${${FIRST_LINE}}")
+  set(LINES)
+  foreach(LINE IN ITEMS "${FIRST_LINE}" ${ARGN})
+    # Expand variable if it is defined and contains another variable.
+    if(DEFINED "${LINE}" AND DEFINED "${${LINE}}")
+      list(APPEND LINES "${${LINE}}" "of variable" "${LINE}")
+    else()
+      list(APPEND LINES "${LINE}")
+    endif()
+  endforeach()
+
+  # Format the first line.
+  list(POP_FRONT LINES LINE)
+  if(DEFINED "${LINE}")
+    set(MESSAGE "${${LINE}}")
     set(PREV_IS_STRING FALSE)
     set(INDENT_VAR FALSE)
   else()
-    set(MESSAGE "${FIRST_LINE}")
+    set(MESSAGE "${LINE}")
     set(PREV_IS_STRING TRUE)
     set(INDENT_VAR TRUE)
   endif()
 
-  foreach(LINE IN ITEMS ${ARGN})
+  # Format the consecutive lines.
+  foreach(LINE IN ITEMS ${LINES})
     if(DEFINED "${LINE}")
       if(PREV_IS_STRING)
         string(APPEND MESSAGE ":")
@@ -106,6 +121,7 @@ macro(fail FIRST_LINE)
     endif()
   endforeach()
 
+  # Throw a fatal error with the formatted message.
   message(FATAL_ERROR "${MESSAGE}")
 endmacro()
 
@@ -185,6 +201,9 @@ function(assert)
         fail("expected test" ARGV2 "not to exist")
         return()
       elseif(ARGV1 STREQUAL "DEFINED")
+        # Unset this to prevent the value from being formatted.
+        unset("${ARGV2}")
+
         fail("expected variable" ARGV2 "not to be defined")
         return()
       elseif(ARGV1 STREQUAL "EXISTS")
@@ -211,78 +230,26 @@ function(assert)
       endif()
     else()
       if(ARGV1 STREQUAL "IN_LIST")
-        if(DEFINED "${ARGV0}")
-          fail("expected string" "${ARGV0}" "of variable" ARGV0
-            "to exist in" "${ARGV2}" "of variable" ARGV2)
-        else()
-          fail("expected string" ARGV0
-            "to exist in" "${ARGV2}" "of variable" ARGV2)
-        endif()
+        fail("expected string" ARGV0 "to exist in" ARGV2)
         return()
       elseif(ARGV1 STREQUAL "MATCHES")
-        if(DEFINED "${ARGV0}")
-          fail("expected string" "${ARGV0}" "of variable" ARGV0
-            "to match" ARGV2)
-        else()
-          fail("expected string" ARGV0 "to match" ARGV2)
-        endif()
+        fail("expected string" ARGV0 "to match" ARGV2)
         return()
       elseif(ARGV1 STREQUAL "STREQUAL")
-        if(DEFINED "${ARGV0}")
-          if(DEFINED "${ARGV2}")
-            fail("expected string" "${ARGV0}" "of variable" ARGV0
-              "to be equal to string" "${ARGV2}" "of variable" ARGV2)
-          else()
-            fail("expected string" "${ARGV0}" "of variable" ARGV0
-              "to be equal to" ARGV2)
-          endif()
-        else()
-          if(DEFINED "${ARGV2}")
-            fail("expected string" ARGV0
-              "to be equal to string" "${ARGV2}" "of variable" ARGV2)
-          else()
-            fail("expected string" ARGV0 "to be equal to" ARGV2)
-          endif()
-        endif()
+        fail("expected string" ARGV0 "to be equal to" ARGV2)
         return()
       endif()
     endif()
   elseif(ARGC EQUAL 4)
     if(ARGV0 STREQUAL "NOT")
       if(ARGV2 STREQUAL "IN_LIST")
-        if(DEFINED "${ARGV1}")
-          fail("expected string" "${ARGV1}" "of variable" ARGV1
-            "not to exist in" "${ARGV3}" "of variable" ARGV3)
-        else()
-          fail("expected string" ARGV1
-            "not to exist in" "${ARGV3}" "of variable" ARGV3)
-        endif()
+        fail("expected string" ARGV1 "not to exist in" ARGV3)
         return()
       elseif(ARGV2 STREQUAL "MATCHES")
-        if(DEFINED "${ARGV1}")
-          fail("expected string" "${ARGV1}" "of variable" ARGV1
-            "not to match" ARGV3)
-        else()
-          fail("expected string" ARGV1 "not to match" ARGV3)
-        endif()
+        fail("expected string" ARGV1 "not to match" ARGV3)
         return()
       elseif(ARGV2 STREQUAL "STREQUAL")
-        if(DEFINED "${ARGV1}")
-          if(DEFINED "${ARGV3}")
-            fail("expected string" "${ARGV1}" "of variable" ARGV1
-              "not to be equal to string" "${ARGV3}" "of variable" ARGV3)
-          else()
-            fail("expected string" "${ARGV1}" "of variable" ARGV1
-              "not to be equal to" ARGV3)
-          endif()
-        else()
-          if(DEFINED "${ARGV3}")
-            fail("expected string" ARGV1
-              "not to be equal to string" "${ARGV3}" "of variable" ARGV3)
-          else()
-            fail("expected string" ARGV1 "not to be equal to" ARGV3)
-          endif()
-        endif()
+        fail("expected string" ARGV1 "not to be equal to" ARGV3)
         return()
       endif()
     endif()

test/assert.cmake

@@ -417,48 +417,6 @@ section("string equality condition assertions")
     endsection()
   endsection()
 
-  section("given a string and a variable")
-    section("it should assert string equality conditions")
-      assert("some string" STREQUAL STRING_VAR)
-      assert(NOT "some string" STREQUAL OTHER_STRING_VAR)
-    endsection()
-
-    section("it should fail to assert string equality conditions")
-      assert_fatal_error(
-        CALL assert NOT "some string" STREQUAL STRING_VAR
-        MESSAGE "expected string:\n  some string\n"
-          "not to be equal to string:\n  some string\n"
-          "of variable:\n  STRING_VAR")
-
-      assert_fatal_error(
-        CALL assert "some string" STREQUAL OTHER_STRING_VAR
-        MESSAGE "expected string:\n  some string\n"
-          "to be equal to string:\n  some other string\n"
-          "of variable:\n  OTHER_STRING_VAR")
-    endsection()
-  endsection()
-
-  section("given a variable and a string")
-    section("it should assert string equality conditions")
-      assert(STRING_VAR STREQUAL "some string")
-      assert(NOT STRING_VAR STREQUAL "some other string")
-    endsection()
-
-    section("it should fail to assert string equality conditions")
-      assert_fatal_error(
-        CALL assert NOT STRING_VAR STREQUAL "some string"
-        MESSAGE "expected string:\n  some string\n"
-          "of variable:\n  STRING_VAR\n"
-          "not to be equal to:\n  some string")
-
-      assert_fatal_error(
-        CALL assert STRING_VAR STREQUAL "some other string"
-        MESSAGE "expected string:\n  some string\n"
-          "of variable:\n  STRING_VAR\n"
-          "to be equal to:\n  some other string")
-    endsection()
-  endsection()
-
   section("given variables")
     section("it should assert string equality conditions")
       assert(STRING_VAR STREQUAL STRING_VAR)
@@ -470,14 +428,14 @@ section("string equality condition assertions")
         CALL assert NOT STRING_VAR STREQUAL STRING_VAR
         MESSAGE "expected string:\n  some string\n"
           "of variable:\n  STRING_VAR\n"
-          "not to be equal to string:\n  some string\n"
+          "not to be equal to:\n  some string\n"
           "of variable:\n  STRING_VAR")
 
       assert_fatal_error(
         CALL assert STRING_VAR STREQUAL OTHER_STRING_VAR
         MESSAGE "expected string:\n  some string\n"
           "of variable:\n  STRING_VAR\n"
-          "to be equal to string:\n  some other string\n"
+          "to be equal to:\n  some other string\n"
           "of variable:\n  OTHER_STRING_VAR")
     endsection()
   endsection()

test/fail.cmake

@@ -16,6 +16,7 @@ endsection()
 
 set(SINGLE "single line variable")
 set(MULTIPLE "multiple\nlines\nvariable")
+set(CONTAINS_SINGLE SINGLE)
 
 section("given variables")
   section("it should fail with a formatted fatal error message")
@@ -27,9 +28,18 @@ section("given variables")
       CALL fail MULTIPLE
       MESSAGE "multiple\nlines\nvariable")
 
+    assert_fatal_error(
+      CALL fail CONTAINS_SINGLE
+      MESSAGE "single line variable\nof variable:\n  SINGLE")
+
     assert_fatal_error(
       CALL fail SINGLE MULTIPLE
       MESSAGE "single line variable\nmultiple\nlines\nvariable")
+
+    assert_fatal_error(
+      CALL fail SINGLE MULTIPLE CONTAINS_SINGLE
+      MESSAGE "single line variable\nmultiple\nlines\nvariable\n"
+        "single line variable\nof variable:\n  SINGLE")
   endsection()
 endsection()
 
@@ -52,13 +62,27 @@ section("given strings and variables")
       MESSAGE "multiple\nlines\nvariable\nmultiple\nlines\nstring")
 
     assert_fatal_error(
-      CALL fail "single line string" "multiple\nlines\nstring" SINGLE MULTIPLE
+      CALL fail "single line string" CONTAINS_SINGLE
+      MESSAGE "single line string:\n  single line variable\n"
+        "of variable:\n  SINGLE")
+
+    assert_fatal_error(
+      CALL fail CONTAINS_SINGLE "single line string"
+      MESSAGE "single line variable\nof variable:\n  SINGLE\n"
+        "single line string")
+
+    assert_fatal_error(
+      CALL fail "single line string" "multiple\nlines\nstring"
+        SINGLE MULTIPLE CONTAINS_SINGLE
       MESSAGE "single line string\nmultiple\nlines\nstring:\n"
-        "  single line variable\n  multiple\n  lines\n  variable")
+        "  single line variable\n  multiple\n  lines\n  variable\n"
+        "  single line variable\nof variable:\n  SINGLE")
 
     assert_fatal_error(
-      CALL fail SINGLE MULTIPLE "single line string" "multiple\nlines\nstring"
+      CALL fail SINGLE MULTIPLE CONTAINS_SINGLE
+        "single line string" "multiple\nlines\nstring"
       MESSAGE "single line variable\nmultiple\nlines\nvariable\n"
+        "single line variable\nof variable:\n  SINGLE\n"
         "single line string\nmultiple\nlines\nstring")
 
     assert_fatal_error(