Add test driver

wcooley · wcooley · commit bb048d7c4ea8 · 2014-05-24T22:56:01.000-07:00
diff --git a/test_cachematrix.R b/test_cachematrix.R
@@ -0,0 +1,61 @@
+library(testthat)
+# I don't know how to make proper packages yet, so I'll hack with `source` for
+# now.
+#library(cachematrix)
+source("cachematrix.R")
+
+# Pre-computed results
+setup_fixtures <- function() {
+    xvect <- c(2,3,0,3,0,2,2,1,1)
+    xm <- matrix(xvect,3,3)
+    xvect_inv <- c(2,3,-6,-1,-2,4,-3,-4,9)
+    xm_inv <- matrix(xvect_inv,3,3)
+
+    xvect2 <- xvect
+    xvect2[1] <- 1
+    xm2 <- matrix(xvect2,3,3)
+    xvect2_inv <- c(-2,-3,6,1,1,-2,3,5,-9)
+    xm2_inv <- matrix(xvect2_inv,3,3)
+
+    list(xm=xm, xm_inv=xm_inv, xm2=xm2, xm2_inv=xm2_inv)
+}
+
+test_that("makeCacheMatrix makes a matrix-ish", {
+    fix <- setup_fixtures()
+
+    cm <- makeCacheMatrix(fix$xm)
+
+    expect_that(cm$get(), equals(fix$xm))
+})
+
+test_that("cacheSolve produces inverted matrix", {
+    fix <- setup_fixtures()
+
+    cm <- makeCacheMatrix(fix$xm)
+    cm_inv <- cacheSolve(cm)
+
+    expect_that(cm_inv, equals(fix$xm_inv))
+
+})
+
+test_that("cacheSolve uses cache", {
+    fix <- setup_fixtures()
+
+    cm <- makeCacheMatrix(fix$xm)
+    cm_inv <- cacheSolve(cm)
+
+    expect_that(cacheSolve(cm), shows_message("getting cached data"))
+})
+
+test_that("set invalidates cache", {
+    fix <- setup_fixtures()
+
+    cm <- makeCacheMatrix(fix$xm)
+    cm_inv <- cacheSolve(cm)
+
+    expect_that(cm$set(fix$xm2), shows_message("invalidating cache"))
+    cm_inv2 <- cacheSolve(cm)
+
+    expect_that(cm_inv2, not(equals(cm_inv)))
+    expect_that(cm_inv2, equals(fix$xm2_inv))
+})
