wal_utils: Add basic set of regression tests for history parsing

wal_utils/.gitignore

+# Ignore test paths
+/results/

wal_utils/Makefile

@@ -3,6 +3,7 @@ MODULES = wal_utils
 EXTENSION = wal_utils
 DATA = wal_utils--1.0.sql
 PGFILEDESC = "wal_utils - Set of tools for WAL data"
+REGRESS = parse_wal_history
 PG_CONFIG = pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)

wal_utils/data/example_success.history

+1	0/09D4F390	no recovery target specified
+2	0/117BEB70	no recovery target specified
+3	0/187BEB38	no recovery target specified
+4	0/188BEB38	no recovery target specified
+5	0/189BEB38	no recovery target specified
+7	0/249BEB38	no recovery target specified

wal_utils/expected/.gitignore

+# Ignore all generated output
+/parse_wal_history.out

wal_utils/input/parse_wal_history.source

+-- Install extension for tests
+CREATE EXTENSION wal_utils;
+
+CREATE TABLE history_data (data text);
+
+-- Note that COPY truncates newlines.
+-- Load history file that succeeds
+COPY history_data FROM '@abs_srcdir@/data/example_success.history' WITH (FORMAT csv);
+SELECT string_agg(data, E'\n') FROM history_data;
+SELECT parse_wal_history(string_agg(data, E'\n')) FROM history_data;
+DROP TABLE history_data;

wal_utils/output/parse_wal_history.source

+-- Install extension for tests
+CREATE EXTENSION wal_utils;
+CREATE TABLE history_data (data text);
+-- Note that COPY truncates newlines.
+-- Load history file that succeeds
+COPY history_data FROM '@abs_srcdir@/data/example_success.history' WITH (FORMAT csv);
+SELECT string_agg(data, E'\n') FROM history_data;
+                      string_agg                      
+------------------------------------------------------
+ 1       0/09D4F390      no recovery target specified+
+ 2       0/117BEB70      no recovery target specified+
+ 3       0/187BEB38      no recovery target specified+
+ 4       0/188BEB38      no recovery target specified+
+ 5       0/189BEB38      no recovery target specified+
+ 7       0/249BEB38      no recovery target specified
+(1 row)
+
+SELECT parse_wal_history(string_agg(data, E'\n')) FROM history_data;
+     parse_wal_history     
+---------------------------
+ (1,,0/9D4F390)
+ (2,0/9D4F390,0/117BEB70)
+ (3,0/117BEB70,0/187BEB38)
+ (4,0/187BEB38,0/188BEB38)
+ (5,0/188BEB38,0/189BEB38)
+ (7,0/189BEB38,0/249BEB38)
+(6 rows)
+
+DROP TABLE history_data;

wal_utils/sql/.gitignore

+# Ignore all generated input
+/parse_wal_history.sql