refactor(api): consistent VALIDATE messages #22262

Problem:
Validation messages are not consistently formatted.
- Parameter names sometimes are NOT quoted.
- Descriptive names (non-parameters) sometimes ARE quoted.

Solution:
Always quote the `name` value passed to a VALIDATE macro _unless_ the
value has whitespace.

2 files changed, 62 insertions, 19 deletions

diff --git a/src/nvim/api/private/validate.c b/src/nvim/api/private/validate.c
index 41c9472a39..c4dd5bcac8 100644
--- a/src/nvim/api/private/validate.c
+++ b/src/nvim/api/private/validate.c
@@ -9,6 +9,55 @@
 # include "api/private/validate.c.generated.h"
 #endif
 
+/// Creates "Invalid …" message and sets it on `err`.
+void api_err_invalid(Error *err, const char *name, const char *val_s, int64_t val_n, bool quote_val)
+{
+  ErrorType errtype = kErrorTypeValidation;
+  // Treat `name` without whitespace as a parameter (surround in quotes).
+  // Treat `name` with whitespace as a description (no quotes).
+  char *has_space = strchr(name, ' ');
+
+  // No value.
+  if (val_s && val_s[0] == '\0') {
+    api_set_error(err, errtype, has_space ? "Invalid %s" : "Invalid '%s'", name);
+    return;
+  }
+
+  // Number value.
+  if (val_s == NULL) {
+    api_set_error(err, errtype, has_space ? "Invalid %s: %" PRId64 : "Invalid '%s': %" PRId64,
+                  name, val_n);
+    return;
+  }
+
+  // String value.
+  if (has_space) {
+    api_set_error(err, errtype, quote_val ? "Invalid %s: '%s'" : "Invalid %s: %s", name, val_s);
+  } else {
+    api_set_error(err, errtype, quote_val ? "Invalid '%s': '%s'" : "Invalid '%s': %s", name, val_s);
+  }
+}
+
+/// Creates "Invalid …: expected …" message and sets it on `err`.
+void api_err_exp(Error *err, const char *name, const char *expected, const char *actual)
+{
+  ErrorType errtype = kErrorTypeValidation;
+  // Treat `name` without whitespace as a parameter (surround in quotes).
+  // Treat `name` with whitespace as a description (no quotes).
+  char *has_space = strchr(name, ' ');
+
+  if (!actual) {
+    api_set_error(err, errtype,
+                  has_space ? "Invalid %s: expected %s" : "Invalid '%s': expected %s",
+                  name, expected);
+    return;
+  }
+
+  api_set_error(err, errtype,
+                has_space ? "Invalid %s: expected %s, got %s" : "Invalid '%s': expected %s, got %s",
+                name, expected, actual);
+}
+
 bool check_string_array(Array arr, char *name, bool disallow_nl, Error *err)
 {
   snprintf(IObuff, sizeof(IObuff), "'%s' item", name);
diff --git a/src/nvim/api/private/validate.h b/src/nvim/api/private/validate.h
index 4a1b99408e..469fed0f83 100644
--- a/src/nvim/api/private/validate.h
+++ b/src/nvim/api/private/validate.h
@@ -4,48 +4,42 @@
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
 
-#define VALIDATE_INT(cond, name, val_, code) \
+#define VALIDATE(cond, fmt_, fmt_arg1, code) \
   do { \
     if (!(cond)) { \
-      api_set_error(err, kErrorTypeValidation, "Invalid " name ": %" PRId64, val_); \
+      api_set_error(err, kErrorTypeValidation, fmt_, fmt_arg1); \
       code; \
     } \
   } while (0)
 
-#define VALIDATE_S(cond, name, val_, code) \
+#define VALIDATE_INT(cond, name, val_, code) \
   do { \
     if (!(cond)) { \
-      if (strequal(val_, "")) { \
-        api_set_error(err, kErrorTypeValidation, "Invalid " name); \
-      } else { \
-        api_set_error(err, kErrorTypeValidation, "Invalid " name ": '%s'", val_); \
-      } \
+      api_err_invalid(err, name, NULL, val_, false); \
       code; \
     } \
   } while (0)
 
-#define VALIDATE_EXP(cond, name, expected, actual, code) \
+#define VALIDATE_S(cond, name, val_, code) \
   do { \
     if (!(cond)) { \
-      api_set_error(err, kErrorTypeValidation, "Invalid %s: expected %s, got %s", \
-                    name, expected, actual); \
+      api_err_invalid(err, name, val_, 0, true); \
       code; \
     } \
   } while (0)
 
-#define VALIDATE_T(name, expected_t, actual_t, code) \
+#define VALIDATE_EXP(cond, name, expected, actual, code) \
   do { \
-    if (expected_t != actual_t) { \
-      api_set_error(err, kErrorTypeValidation, "Invalid %s: expected %s, got %s", \
-                    name, api_typename(expected_t), api_typename(actual_t)); \
+    if (!(cond)) { \
+      api_err_exp(err, name, expected, actual); \
       code; \
     } \
   } while (0)
 
-#define VALIDATE(cond, fmt_, fmt_arg1, code) \
+#define VALIDATE_T(name, expected_t, actual_t, code) \
   do { \
-    if (!(cond)) { \
-      api_set_error(err, kErrorTypeValidation, fmt_, fmt_arg1); \
+    if (expected_t != actual_t) { \
+      api_err_exp(err, name, api_typename(expected_t), api_typename(actual_t)); \
       code; \
     } \
   } while (0)
@@ -53,7 +47,7 @@
 #define VALIDATE_RANGE(cond, name, code) \
   do { \
     if (!(cond)) { \
-      api_set_error(err, kErrorTypeValidation, "Invalid '%s': out of range", name); \
+      api_err_invalid(err, name, "out of range", 0, false); \
       code; \
     } \
   } while (0)