library(vegan)
data(varechem)
data(varespec)

test_that("betaStability single method (linearPred) works correctly", {
    result <- betaStability(
        comtable = varespec,
        envmeta = varechem,
        method = "linearPred"
    )

    # Check no error
    expect_no_error(result)

    # Check result is a data frame
    expect_s3_class(result, "data.frame")

    # Check has exactly 1 column
    expect_equal(ncol(result), 1)

    # Check column name
    expect_equal(colnames(result), "stability_Linear")

    # Check number of rows matches number of sites
    expect_equal(nrow(result), nrow(varespec))
})

test_that("betaStability multiple methods works correctly", {
    result <- betaStability(
        comtable = varespec,
        envmeta = varechem,
        method = c("linearPred", "mlPred")
    )

    # Check no error
    expect_no_error(result)

    # Check result is a data frame
    expect_s3_class(result, "data.frame")

    # Check has exactly 2 columns
    expect_equal(ncol(result), 2)

    # Check column names match the methods
    expect_equal(colnames(result), c("linearPred", "mlPred"))

    # Check number of rows matches number of sites
    expect_equal(nrow(result), nrow(varespec))
})