mfdb: Remove now-useless check_db_available

All the examples that did use it are converted to DuckDB, which is
always available unlike a postgresql DB.

Makefile

@@ -16,10 +16,10 @@ build:
 	R CMD build .
 
 check: build
-	LANGUAGE="en" MFDB_FORCE_AVAILABLE="y" R --vanilla --slave CMD check "$(TARBALL)"
+	LANGUAGE="en" R --vanilla --slave CMD check "$(TARBALL)"
 
 check-as-cran: build
-	MFDB_FORCE_AVAILABLE="y" R --vanilla --slave CMD check --as-cran "$(TARBALL)"
+	R --vanilla --slave CMD check --as-cran "$(TARBALL)"
 
 wincheck: build
 	# See https://win-builder.r-project.org/ for more information

R/mfdb.R

@@ -2,7 +2,6 @@
 mfdb <- function(schema_name = "",
                  db_params = list(),
                  destroy_schema = FALSE,
-                 check_db_available = FALSE,
                  save_temp_tables = FALSE) {
     logger <- logging::getLogger('mfdb')
     is_sqlite_dbname <- function (x) grepl("\\.sqlite3?$", x)
@@ -86,13 +85,6 @@ mfdb <- function(schema_name = "",
         }
     }
 
-    if (check_db_available) {
-        # Just check we managed to make a connection, for examples
-        if (nzchar(Sys.getenv('MFDB_FORCE_AVAILABLE'))) return (TRUE)
-        if (!("error" %in% class(db_connection))) return(TRUE)
-        return(FALSE)
-    }
-
     if ("error" %in% class(db_connection)) {
         stop("Could not connect to mf database: ", paste(db_connection$message, collapse = "\n"))
     }

man/mfdb.Rd

@@ -11,7 +11,6 @@
     mfdb(schema_name,
          db_params = list(),
          destroy_schema = FALSE,
-         check_db_available = FALSE,
          save_temp_tables = FALSE)
 
     mfdb_disconnect(mdb)
@@ -60,10 +59,6 @@
         Optional boolean. If true, any temporary tables will be made permanent
         for later inspection.
     }
-    \item{check_db_available}{
-        Optionabl boolean. If true, we will only check that the datbase
-        connection could be made. Mostly for use in examples.
-    }
     \item{mdb}{
         Database connection created by \code{mfdb()}.
     }

tests/test-mfdb.R

@@ -73,12 +73,5 @@ ok_group("mfdb", {
         ok(cmp(attempts, list(
             list(host = "mfdb.rhi.hi.is", user = "polly", password = "ppwd", dbname = "dbname=mf sslmode=require", drv = pq_driver)
         )), "Used special mfdb server parameters")
-
-        old_force <- Sys.getenv('MFDB_FORCE_AVAILABLE')
-        Sys.setenv(MFDB_FORCE_AVAILABLE = "")
-        ok(cmp(mfdb(check_db_available = T), FALSE), "Didn't error with check_db_available, just return FALSE")
-        Sys.setenv(MFDB_FORCE_AVAILABLE = "T")
-        ok(cmp(mfdb(check_db_available = T), TRUE), "MFDB_FORCE_AVAILABLE on, returned TRUE anyway")
-        Sys.setenv(MFDB_FORCE_AVAILABLE = old_force)
     })
 })