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.

1 files changed, 49 insertions, 0 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);