no-mistakes(review): apply reviewer inline fixes

Author: dmealing

CHANGELOG.md

@@ -27,8 +27,9 @@ here.**
   literal's `::text` was already folded away but the column's was not, so a database `migrate`
   had just built showed the same constraint as both added and dropped. The comparison now
   drops a `::text` cast only when it sits directly before a regex-match operator (`~`, `~*`,
-  `!~`, `!~*`), where the uncast spelling is the only valid one; a changed pattern or any
-  other cast still reads as drift. Schema comparison is TypeScript-owned, so no other port
+  `!~`, `!~*`), whatever the column type; a changed pattern or any other cast still reads as
+  drift. Known gap: on a `citext` column the cast and uncast spellings differ in meaning
+  (case-sensitive vs case-insensitive) but compare equal. Schema comparison is TypeScript-owned, so no other port
   carries this comparison.
 
 - **The api reference now follows a routes generator's `filter` as well as its `expose`.**

server/typescript/packages/migrate-ts/src/check-expr-compare.ts

@@ -195,8 +195,11 @@ function readCastTarget(s: string, i: number): { type: string; consumed: number
 function isElidableCast(type: string, lhs: string, rest: string): boolean {
   // `::text` directly before a regex-match operator (`~`, `~*`, `!~`, `!~*`). Those
   // operators are defined on text, so on a varchar/text column PG adds the cast itself
-  // (`"key" ~ '…'` comes back `((key)::text ~ '…'::text)`), and on any other column type
-  // the uncast spelling is not valid SQL — so a cast here is never the author's meaning.
+  // (`"key" ~ '…'` comes back `((key)::text ~ '…'::text)`). The comparator sees only the
+  // expression string, never the column type, so this elides the cast for every column.
+  // Known gap: on a `citext` column `col::text ~ 'A'` (case-sensitive) and `col ~ 'A'`
+  // (citext's own case-insensitive operator) both normalize alike, so switching between
+  // the two spellings reads as clean.
   if (type === "text" && /^\s*!?~\*?(?![-+*\/<>=~!@#%^&|?])/.test(rest)) return true;
   // `->>` / `#>>` yield text; a following `::text` cannot change anything.
   if (type === "text" && /(?:->>|#>>)\s*(?:'(?:[^']|'')*'|[\w."]+)$/.test(lhs)) return true;