test_controls.R
In scip: Interface to the SCIP Optimization Suite

library(scip)

## -----------------------------------------------------------------------
## Test 1: Default control values
## -----------------------------------------------------------------------
ctrl <- scip_control()
expect_true(ctrl$verbose)
expect_true(inherits(ctrl, "scip_control"))
expect_equal(length(ctrl$scip_params), 0L)

## -----------------------------------------------------------------------
## Test 2: Custom control values — R-friendly parameter names
## -----------------------------------------------------------------------
ctrl2 <- scip_control(verbose = FALSE, time_limit = 10, gap_limit = 0.01)
expect_false(ctrl2$verbose)
expect_equal(ctrl2$scip_params[["display/verblevel"]], 0L)
expect_equal(ctrl2$scip_params[["limits/time"]], 10)
expect_equal(ctrl2$scip_params[["limits/gap"]], 0.01)

## -----------------------------------------------------------------------
## Test 3: Extra SCIP parameters pass-through via ...
## -----------------------------------------------------------------------
ctrl3 <- scip_control("lp/fastmip" = 1L)
expect_true(!is.null(ctrl3$scip_params))
expect_equal(ctrl3$scip_params[["lp/fastmip"]], 1L)

## -----------------------------------------------------------------------
## Test 4: Presolving off sets presolving/maxrounds to 0
## -----------------------------------------------------------------------
ctrl4 <- scip_control(presolving = FALSE)
expect_equal(ctrl4$scip_params[["presolving/maxrounds"]], 0L)

## -----------------------------------------------------------------------
## Test 5: Node limit
## -----------------------------------------------------------------------
ctrl5 <- scip_control(node_limit = 500L)
expect_equal(ctrl5$scip_params[["limits/nodes"]], 500L)

## -----------------------------------------------------------------------
## Test 6: Heuristics emphasis
## -----------------------------------------------------------------------
ctrl6 <- scip_control(heuristics_emphasis = "aggressive")
expect_equal(ctrl6$heuristics_emphasis, "aggressive")

## -----------------------------------------------------------------------
## Test 7: Print method works
## -----------------------------------------------------------------------
expect_true(is.character(capture.output(print(ctrl2))))

## -----------------------------------------------------------------------
## Test 8: Verbose off suppresses output
## -----------------------------------------------------------------------
A <- matrix(c(1, 1), nrow = 1)
b <- 2
res <- scip_solve(
    obj   = c(-1, -1),
    A     = A,
    b     = b,
    sense = "<=",
    control = list(verbose = FALSE)
)
expect_equal(res$status, "optimal")

## -----------------------------------------------------------------------
## Test 9: Solve with scip_control object directly
## -----------------------------------------------------------------------
res2 <- scip_solve(
    obj   = c(-1, -1),
    A     = A,
    b     = b,
    sense = "<=",
    control = scip_control(verbose = FALSE)
)
expect_equal(res2$status, "optimal")

## -----------------------------------------------------------------------
## Test 10: Solution limit — from SCIP's limit tests
## -----------------------------------------------------------------------
A5 <- matrix(c(1, 1, 1, 0, 0, 1), nrow = 3, byrow = TRUE)
b5 <- c(10, 6, 8)
res5 <- scip_solve(
    obj   = c(-1, -1),
    A     = A5,
    b     = b5,
    sense = rep("<=", 3),
    vtype = "I",
    control = list(verbose = FALSE, sol_limit = 1L)
)
expect_true(res5$status %in% c("optimal", "sollimit"))
expect_true(res5$sol_count >= 1L)