Refactor and add tests

.gitignore

@@ -0,0 +1,2 @@
+data
+output.txt

lints.sql

@@ -1,6 +1,8 @@
 create temporary view tables as
-    -- select * from sqlite_schema where type = 'table';
-    select l.* from sqlite_schema s left join pragma_table_list l on s.name = l.name where s.type = 'table';
+    select l.*
+      from sqlite_schema s
+ left join pragma_table_list l on s.name = l.name
+     where s.type = 'table';
 
 
 create temporary view columns as
@@ -24,30 +26,23 @@ create temporary view columns as
 -- Require all fields to be not null, unless they are foreign keys
 create temporary view lint_check__require_not_null as
     select 'Column should should be "not null"' as error_msg,
-           tables.name as table_name,
-           table_info.name as column_name
-      from tables
-      join pragma_table_info(tables.name) as table_info
-     where not exists (
-                select 1 from pragma_foreign_key_list(tables.name) as fk
-                 where fk."from" = table_info.name
-               )
-       and (table_info."notnull" = 0 and table_info.pk = 0);
+           table_name,
+           column_name
+      from columns
+     where columns."notnull" = 0
+       and fk_target_column is null
+       and is_primary_key = 0; -- primary keys are automatically not-null, but aren't listed as such in pragma_table_info
 
 
 -- Require all non-foreign-key, non-primary-key fields to have a default value
 create temporary view lint_check__require_default_values as
     select 'Column should have a default value' as error_msg,
-           tables.name as table_name,
-           table_info.name as column_name
-      from tables
-      join pragma_table_info(tables.name) as table_info
-     where table_info.pk = 0
-       and not exists (
-                select 1 from pragma_foreign_key_list(tables.name) as fk
-                 where fk."from" = table_info.name
-               )
-       and table_info.dflt_value is null;
+           table_name,
+           column_name
+      from columns
+     where table_info.dflt_value is null
+       and fk_target_column is null
+       and is_primary_key = 0;
 
 
 -- All tables should be STRICT (must specify column types; types must be int, integer, real, text,
@@ -58,18 +53,16 @@ create temporary view lint_check__require_strict as
            name as table_name,
            '' as column_name
       from tables
-     where strict = 0
-       and name not in ('sqlite_schema', 'sqlite_temp_schema');
+     where strict = 0;
 
 
 -- Forbid use 'int' column types
 create temporary view lint_check__forbid_int_type as
     select 'Column should use "integer" type instead of "int"' as error_msg,
-           tables.name as table_name,
-           table_info.name as column_name
-      from tables
-      join pragma_table_info(tables.name) as table_info
-     where table_info.type like 'int';
+           table_name,
+           column_name
+      from columns
+     where column_type like 'int';
 
 
 -- tables must have a primary key; if it's rowid, it has to be named explicitly
@@ -78,42 +71,35 @@ create temporary view lint_check__require_explicit_primary_key as
            tables.name as table_name,
            '' as column_name
       from tables
-     where not exists (select name from pragma_table_info(tables.name) where pk != 0);
+     where not exists (select 1 from pragma_table_info(tables.name) where pk != 0);
 
 
 -- columns referenced by foreign keys must have indexes
 create temporary view lint_check__require_indexes_for_foreign_keys as
 with index_info as (
-        select indexes.name as index_name,
-               tables.name as table_name,
-               columns.name as column_name,
-               case when origin = 'c' then 'regular' when origin = 'u' then 'unique' when origin = 'pk' then 'primary key' else origin end as index_type
+        select tables.name as table_name,
+               columns.name as column_name
           from tables
           join pragma_index_list(tables.name) as indexes
           join pragma_index_info(indexes.name) as columns
 
          union
 
-        select '[auto-generated rowid primary key index]' as index_name,
-               tables.name as table_name,
-               columns.name as column_name,
-               'primary key' as index_type
-          from tables
-          join pragma_table_info(tables.name) as "columns"
-         where columns.name = 'rowid'
-           and columns.pk != 0 -- `pk` is either 0, or the 1-based index of the column within the primary key
-    ), foreign_key_targets as (
-        select tables.name as "fk_source_table",
-               fk."from" as "fk_source_column",
-               fk."table" as fk_target_table,
-               fk."to" as fk_target_column
-          from tables
-          join pragma_foreign_key_list(tables.name) as fk
+        select table_name,
+               column_name
+          from columns
+         where column_name = 'rowid'
+           and is_primary_key != 0 -- `pk` is either 0, or the 1-based index of the column within the primary key
+    ), foreign_keys as (
+        select * from columns where fk_target_column is not null
     )
-select fk_source_table, fk_source_column, fk_target_table, fk_target_column, ifnull(index_info.table_name, 'NULL') as index_table, ifnull(index_info.column_name, 'NULL') as index_column
-  from foreign_key_targets
-  left join index_info on foreign_key_targets.fk_target_table = index_info.table_name and foreign_key_targets.fk_target_column = index_info.column_name
- where index_column = 'NULL';
+select 'Foreign keys should point to indexed columns' as error_msg,
+       foreign_keys.table_name as table_name,
+       foreign_keys.column_name as column_name
+  from foreign_keys
+  left join index_info on foreign_keys.fk_target_table = index_info.table_name
+                      and foreign_keys.fk_target_column = index_info.column_name
+ where index_info.column_name is null;
 
 
 -- ==============
@@ -133,9 +119,6 @@ select * from (
  union
     select * from lint_check__require_explicit_primary_key
  union
-    select 'Foreign keys should point to indexed columns' as error_msg,
-           fk_source_table as table_name,
-           fk_source_column as column_name
-      from lint_check__require_indexes_for_foreign_keys
+    select * from lint_check__require_indexes_for_foreign_keys
 );
 

test.sh

@@ -0,0 +1,27 @@
+#!/bin/sh
+
+rm data/*
+for file in test_schemas/failure-*; do
+	echo "Testing '$file'"
+	test -e output.txt && rm output.txt
+	db_path="data/$(basename $file).db"
+	sqlite3 $db_path < $file
+	sqlite3 -column -header $db_path < lints.sql | tee output.txt
+	if [ ! -s output.txt ]; then
+		echo "Should have failed, but didn't: $file"
+		exit 1
+	fi
+done
+
+file="test_schemas/success.sql"
+echo "Testing '$file'"
+test -e output.txt && rm output.txt
+db_path="data/$(basename $file).db"
+sqlite3 $db_path < $file
+sqlite3 -column -header $db_path < lints.sql | tee output.txt
+if [ -s output.txt ]; then
+	echo "Should have passed, but didn't: $file"
+	exit 1
+fi
+
+echo "Tests passed!"