fix: correct type inference for arithmetic operations (#359)

This update addresses an issue where the inferred type was incorrect when dealing with arithmetic operations in SQL queries. The changes ensure that the type is accurately resolved based on the operation and operand types.

.changeset/chatty-hairs-hide.md

@@ -0,0 +1,5 @@
+---
+"@ts-safeql/generate": patch
+---
+
+fixed an issue where the inferred typed was incorrect when dealing with arithmetic operations

packages/eslint-plugin/src/rules/check-sql.test.ts

@@ -1290,7 +1290,7 @@ RuleTester.describe("check-sql", () => {
           await sql<Caregiver[]>\`
             SELECT
               CASE WHEN caregiver.id IS NOT NULL
-                THEN jsonb_build_object('is_test', caregiver.middle_name NOT LIKE '%test%')
+                THEN jsonb_build_object('is_test', caregiver.first_name LIKE '%test%')
                 ELSE NULL
               END AS meta
             FROM

packages/generate/src/ast-decribe.utils.ts

@@ -28,6 +28,6 @@ export function isSingleCell<T>(arr: T[]): arr is [T] {
   return arr.length === 1;
 }
 
-function isTuple<T>(arr: T[]): arr is [T, T] {
+export function isTuple<T>(arr: T[]): arr is [T, T] {
   return arr.length === 2;
 }

packages/generate/src/ast-describe.ts

@@ -1,11 +1,12 @@
-import { fmap, normalizeIndent } from "@ts-safeql/shared";
+import { defaultTypeExprMapping, fmap, normalizeIndent } from "@ts-safeql/shared";
 import * as LibPgQueryAST from "@ts-safeql/sql-ast";
 import {
   isColumnStarRef,
   isColumnTableColumnRef,
   isColumnTableStarRef,
   isColumnUnknownRef,
   isSingleCell,
+  isTuple,
 } from "./ast-decribe.utils";
 import { ResolvedColumn, SourcesResolver, getSources } from "./ast-get-sources";
 import { PgColRow, PgEnumsMaps, PgTypesMap } from "./generate";
@@ -20,7 +21,7 @@ type ASTDescriptionOptions = {
   pgColsBySchemaAndTableName: Map<string, Map<string, PgColRow[]>>;
   pgTypes: PgTypesMap;
   pgEnums: PgEnumsMaps;
-  pgFns: Map<string, string>;
+  pgFns: Map<string, { ts: string; pg: string }>;
 };
 
 type ASTDescriptionContext = ASTDescriptionOptions & {
@@ -38,7 +39,7 @@ export type ASTDescribedColumnType =
   | { kind: "union"; value: ASTDescribedColumnType[] }
   | { kind: "array"; value: ASTDescribedColumnType }
   | { kind: "object"; value: [string, ASTDescribedColumnType][] }
-  | { kind: "type"; value: string }
+  | { kind: "type"; value: string; type: string }
   | { kind: "literal"; value: string; base: ASTDescribedColumnType };
 
 export function getASTDescription(params: ASTDescriptionOptions): Map<number, ASTDescribedColumn> {
@@ -82,20 +83,32 @@ export function getASTDescription(params: ASTDescriptionOptions): Map<number, AS
       p: { oid: number; baseOid: number | null } | { name: string },
     ): ASTDescribedColumnType => {
       if ("name" in p) {
-        return { kind: "type", value: params.typesMap.get(p.name)?.value ?? "unknown" };
+        return {
+          kind: "type",
+          value: params.typesMap.get(p.name)?.value ?? "unknown",
+          type: p.name,
+        };
       }
 
       const typeByOid = getTypeByOid(p.oid);
 
       if (typeByOid.override) {
-        const baseType: ASTDescribedColumnType = { kind: "type", value: typeByOid.value };
+        const baseType: ASTDescribedColumnType = {
+          kind: "type",
+          value: typeByOid.value,
+          type: params.pgTypes.get(p.oid)?.name ?? "unknown",
+        };
         return typeByOid.isArray ? { kind: "array", value: baseType } : baseType;
       }
 
       const typeByBaseOid = fmap(p.baseOid, getTypeByOid);
 
       if (typeByBaseOid?.override === true) {
-        const baseType: ASTDescribedColumnType = { kind: "type", value: typeByBaseOid.value };
+        const baseType: ASTDescribedColumnType = {
+          kind: "type",
+          value: typeByBaseOid.value,
+          type: params.pgTypes.get(p.baseOid!)?.name ?? "unknown",
+        };
         return typeByBaseOid.isArray ? { kind: "array", value: baseType } : baseType;
       }
 
@@ -104,13 +117,21 @@ export function getASTDescription(params: ASTDescriptionOptions): Map<number, AS
       if (enumValue !== undefined) {
         return {
           kind: "union",
-          value: enumValue.values.map((value) => ({ kind: "type", value: `'${value}'` })),
+          value: enumValue.values.map((value) => ({
+            kind: "type",
+            value: `'${value}'`,
+            type: enumValue.name,
+          })),
         };
       }
 
       const { isArray, value } = typeByBaseOid ?? typeByOid;
 
-      const type: ASTDescribedColumnType = { kind: "type", value: value };
+      const type: ASTDescribedColumnType = {
+        kind: "type",
+        value: value,
+        type: params.pgTypes.get(p.oid)?.name ?? "unknown",
+      };
 
       return isArray ? { kind: "array", value: type } : type;
     },
@@ -215,15 +236,81 @@ function getDescribedNode(params: {
 
 function getDescribedAExpr({
   alias,
+  node,
   context,
 }: GetDescribedParamsOf<LibPgQueryAST.AExpr>): ASTDescribedColumn[] {
+  const name = alias ?? "?column?";
+
+  if (node.lexpr === undefined && node.rexpr !== undefined) {
+    const described = getDescribedNode({ alias, node: node.rexpr, context }).at(0);
+    const type = fmap(described, (x) => getBaseType(x.type));
+
+    if (type === null) return [];
+
+    return [{ name, type }];
+  }
+
+  if (node.lexpr === undefined || node.rexpr === undefined) {
+    return [];
+  }
+
+  const getResolvedNullableValueOrNull = (node: LibPgQueryAST.Node) => {
+    const column = getDescribedNode({ alias: undefined, node, context }).at(0);
+
+    if (column === undefined) return null;
+
+    if (column.type.kind === "array") {
+      return { value: "array", nullable: false };
+    }
+
+    if (column.type.kind === "type") {
+      return { value: column.type.type, nullable: false };
+    }
+
+    if (column.type.kind === "literal" && column.type.base.kind === "type") {
+      return { value: column.type.base.type, nullable: false };
+    }
+
+    if (column.type.kind === "union" && isTuple(column.type.value)) {
+      let nullable = false;
+      let value: string | undefined = undefined;
+
+      for (const type of column.type.value) {
+        if (type.kind !== "type") return null;
+        if (type.value === "null") nullable = true;
+        if (type.value !== "null") value = type.type;
+      }
+
+      if (value === undefined) return null;
+
+      return { value, nullable };
+    }
+
+    return null;
+  };
+
+  const lnode = getResolvedNullableValueOrNull(node.lexpr);
+  const rnode = getResolvedNullableValueOrNull(node.rexpr);
+
+  if (lnode === null || rnode === null) {
+    return [];
+  }
+
+  const operator = concatStringNodes(node.name);
+  const resolved: string | undefined =
+    defaultTypeExprMapping[`${lnode.value} ${operator} ${rnode.value}`];
+
+  if (resolved === undefined) {
+    return [];
+  }
+
   return [
     {
-      name: alias ?? "?column?",
+      name: name,
       type: resolveType({
         context: context,
-        nullable: false,
-        type: context.toTypeScriptType({ name: "boolean" }),
+        nullable: !context.nonNullableColumns.has(name) && (lnode.nullable || rnode.nullable),
+        type: context.toTypeScriptType({ name: resolved }),
       }),
     },
   ];
@@ -239,7 +326,7 @@ function getDescribedNullTest({
       type: resolveType({
         context: context,
         nullable: false,
-        type: context.toTypeScriptType({ name: "boolean" }),
+        type: context.toTypeScriptType({ name: "bool" }),
       }),
     },
   ];
@@ -298,7 +385,7 @@ function getDescribedBoolExpr({
       type: resolveType({
         context: context,
         nullable: false,
-        type: context.toTypeScriptType({ name: "boolean" }),
+        type: context.toTypeScriptType({ name: "bool" }),
       }),
     },
   ];
@@ -317,7 +404,7 @@ function getDescribedSubLink({
         nullable: false,
         type: (() => {
           if (node.subLinkType === LibPgQueryAST.SubLinkType.EXISTS_SUBLINK) {
-            return context.toTypeScriptType({ name: "boolean" });
+            return context.toTypeScriptType({ name: "bool" });
           }
 
           return context.toTypeScriptType({ name: "unknown" });
@@ -412,7 +499,7 @@ function mergeDescribedColumnTypes(types: ASTDescribedColumnType[]): ASTDescribe
 
   if (!seenSymbols.has("boolean") && seenSymbols.has("true") && seenSymbols.has("false")) {
     seenSymbols.add("boolean");
-    result.push({ kind: "type", value: "boolean" });
+    result.push({ kind: "type", value: "boolean", type: "bool" });
   }
 
   if (seenSymbols.has("boolean") && (seenSymbols.has("true") || seenSymbols.has("false"))) {
@@ -537,15 +624,15 @@ function getDescribedFuncCallByPgFn({
 
   const pgFnValue =
     args.length === 0
-      ? context.pgFns.get(functionName)
+      ? (context.pgFns.get(functionName) ?? context.pgFns.get(`${functionName}(string)`))
       : (context.pgFns.get(`${functionName}(${args.join(", ")})`) ??
         context.pgFns.get(`${functionName}(any)`) ??
         context.pgFns.get(`${functionName}(unknown)`));
 
   const type = resolveType({
     context: context,
     nullable: !context.nonNullableColumns.has(name),
-    type: { kind: "type", value: pgFnValue ?? "unknown" },
+    type: { kind: "type", value: pgFnValue?.ts ?? "unknown", type: pgFnValue?.pg ?? "unknown" },
   });
 
   return [{ name, type }];
@@ -758,7 +845,11 @@ function getDescribedColumnByResolvedColumns(params: {
         ?.get(column.colName);
 
       if (overridenType !== undefined) {
-        return { kind: "type", value: overridenType };
+        return {
+          kind: "type",
+          value: overridenType,
+          type: params.context.pgTypes.get(column.colTypeOid)?.name ?? "unknown",
+        };
       }
 
       return params.context.toTypeScriptType({
@@ -789,7 +880,7 @@ function getDescribedAConst({
         return {
           kind: "literal",
           value: node.boolval.boolval ? "true" : "false",
-          base: context.toTypeScriptType({ name: "boolean" }),
+          base: context.toTypeScriptType({ name: "bool" }),
         };
       case node.bsval !== undefined:
         return context.toTypeScriptType({ name: "bytea" });
@@ -838,7 +929,7 @@ function asNonNullableType(type: ASTDescribedColumnType): ASTDescribedColumnType
       );
 
       if (filtered.length === 0) {
-        return { kind: "type", value: "unknown" };
+        return { kind: "type", value: "unknown", type: "unknown" };
       }
 
       if (filtered.length === 1) {
@@ -848,7 +939,7 @@ function asNonNullableType(type: ASTDescribedColumnType): ASTDescribedColumnType
       return { kind: "union", value: filtered };
     }
     case "type":
-      return type.value === "null" ? { kind: "type", value: "unknown" } : type;
+      return type.value === "null" ? { kind: "type", value: "unknown", type: "unknown" } : type;
   }
 }