tell travis to run the tests

.travis.yml

-sudo: false
-script: exit 0
+language: bash
+sudo: required
+services:
+  - docker
+install: docker pull heroku/cedar:14
+script: make test

Makefile

 # These targets are not files
 .PHONY: tests
 
-tests:
-	./bin/test
+test: test-cedar-14
+
+test-cedar-14:
+	@echo "Running tests in docker (cedar-14)..."
+	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=cedar-14" heroku/cedar:14 bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
+	@echo ""
 
 tools:
 	git clone https://github.com/kennethreitz/pip-pop.git

test/fixtures/psycopg2/requirements.txt

+psycopg2
\ No newline at end of file

test/fixtures/requirements-standard/requirements.txt

+requests
\ No newline at end of file

test/run

+#!/usr/bin/env bash
+# See README.md for info on running these tests.
+
+testStandardRequirements() {
+  compile "requirements-standard"
+  assertCaptured "requests"
+  assertCapturedSuccess
+}
+
+testPsycopg2() {
+  compile "psycopg2"
+  assertCaptured "psycopg2"
+  assertCapturedSuccess
+}
+
+pushd $(dirname 0) >/dev/null
+popd >/dev/null
+
+source $(pwd)/test/utils
+
+mktmpdir() {
+  dir=$(mktemp -t testXXXXX)
+  rm -rf $dir
+  mkdir $dir
+  echo $dir
+}
+
+detect() {
+  capture $(pwd)/bin/detect $(pwd)/test/fixtures/$1
+}
+
+compile_dir=""
+
+default_process_types_cleanup() {
+  file="/tmp/default_process_types"
+  if [ -f "$file" ]; then
+    rm "$file"
+  fi
+}
+
+compile() {
+  default_process_types_cleanup
+  bp_dir=$(mktmpdir)
+  compile_dir=$(mktmpdir)
+  cp -a $(pwd)/* ${bp_dir}
+  cp -a ${bp_dir}/test/fixtures/$1/. ${compile_dir}
+  capture ${bp_dir}/bin/compile ${compile_dir} ${2:-$(mktmpdir)} $3
+}
+
+compileDir() {
+  default_process_types_cleanup
+
+  local bp_dir=$(mktmpdir)
+  local compile_dir=${1:-$(mktmpdir)}
+  local cache_dir=${2:-$(mktmpdir)}
+  local env_dir=$3
+
+  cp -a $(pwd)/* ${bp_dir}
+  capture ${bp_dir}/bin/compile ${compile_dir} ${cache_dir} ${env_dir}
+}
+
+release() {
+  bp_dir=$(mktmpdir)
+  cp -a $(pwd)/* ${bp_dir}
+  capture ${bp_dir}/bin/release ${bp_dir}/test/fixtures/$1
+}
+
+assertFile() {
+  assertEquals "$1" "$(cat ${compile_dir}/$2)"
+}
+
+source $(pwd)/test/shunit2

test/utils

+#!/bin/sh
+
+# taken from
+# https://github.com/ryanbrainard/heroku-buildpack-testrunner/blob/master/lib/test_utils.sh
+
+oneTimeSetUp()
+{
+   TEST_SUITE_CACHE="$(mktemp -d ${SHUNIT_TMPDIR}/test_suite_cache.XXXX)"
+}
+
+oneTimeTearDown()
+{
+  rm -rf ${TEST_SUITE_CACHE}
+}
+
+setUp()
+{
+  OUTPUT_DIR="$(mktemp -d ${SHUNIT_TMPDIR}/output.XXXX)"
+  STD_OUT="${OUTPUT_DIR}/stdout"
+  STD_ERR="${OUTPUT_DIR}/stderr"
+  BUILD_DIR="${OUTPUT_DIR}/build"
+  CACHE_DIR="${OUTPUT_DIR}/cache"
+  mkdir -p ${OUTPUT_DIR}
+  mkdir -p ${BUILD_DIR}
+  mkdir -p ${CACHE_DIR}
+}
+
+tearDown()
+{
+  rm -rf ${OUTPUT_DIR}
+}
+
+capture()
+{
+  resetCapture
+
+  LAST_COMMAND="$@"
+
+  $@ >${STD_OUT} 2>${STD_ERR}
+  RETURN=$?
+  rtrn=${RETURN} # deprecated
+}
+
+resetCapture()
+{
+  if [ -f ${STD_OUT} ]; then
+    rm ${STD_OUT}
+  fi
+
+  if [ -f ${STD_ERR} ]; then
+    rm ${STD_ERR}
+  fi
+
+  unset LAST_COMMAND
+  unset RETURN
+  unset rtrn # deprecated
+}
+
+detect()
+{
+  capture ${BUILDPACK_HOME}/bin/detect ${BUILD_DIR}
+}
+
+compile()
+{
+  capture ${BUILDPACK_HOME}/bin/compile ${BUILD_DIR} ${CACHE_DIR}
+}
+
+release()
+{
+  capture ${BUILDPACK_HOME}/bin/release ${BUILD_DIR}
+}
+
+assertCapturedEquals()
+{
+  assertEquals "$@" "$(cat ${STD_OUT})"
+}
+
+assertCapturedNotEquals()
+{
+  assertNotEquals "$@" "$(cat ${STD_OUT})"
+}
+
+assertCaptured()
+{
+  assertFileContains "$@" "${STD_OUT}"
+}
+
+assertNotCaptured()
+{
+  assertFileNotContains "$@" "${STD_OUT}"
+}
+
+assertCapturedSuccess()
+{
+  assertEquals "Expected captured exit code to be 0; was <${RETURN}>" "0" "${RETURN}"
+  assertEquals "Expected STD_ERR to be empty; was <$(cat ${STD_ERR})>" "" "$(cat ${STD_ERR})"
+}
+
+# assertCapturedError [[expectedErrorCode] expectedErrorMsg]
+assertCapturedError()
+{
+  if [ $# -gt 1 ]; then
+    local expectedErrorCode=${1}
+    shift
+  fi
+
+  local expectedErrorMsg=${1:-""}
+
+  if [ -z ${expectedErrorCode} ]; then
+    assertTrue "Expected captured exit code to be greater than 0; was <${RETURN}>" "[ ${RETURN} -gt 0 ]"
+  else
+    assertTrue "Expected captured exit code to be <${expectedErrorCode}>; was <${RETURN}>" "[ ${RETURN} -eq ${expectedErrorCode} ]"
+  fi
+
+  if [ "${expectedErrorMsg}" != "" ]; then
+    assertFileContains "Expected STD_ERR to contain error <${expectedErrorMsg}>" "${expectedErrorMsg}" "${STD_ERR}"
+  fi
+}
+
+_assertContains()
+{
+  if [ 5 -eq $# ]; then
+    local msg=$1
+    shift
+  elif [ ! 4 -eq $# ]; then
+    fail "Expected 4 or 5 parameters; Receieved $# parameters"
+  fi
+
+  local needle=$1
+  local haystack=$2
+  local expectation=$3
+  local haystack_type=$4
+
+  case "${haystack_type}" in
+    "file") grep -q -F -e "${needle}" ${haystack} ;;
+    "text") echo "${haystack}" | grep -q -F -e "${needle}" ;;
+  esac
+
+  if [ "${expectation}" != "$?" ]; then
+    case "${expectation}" in
+      0) default_msg="Expected <${haystack}> to contain <${needle}>" ;;
+      1) default_msg="Did not expect <${haystack}> to contain <${needle}>" ;;
+    esac
+
+    fail "${msg:-${default_msg}}"
+  fi
+}
+
+assertContains()
+{
+  _assertContains "$@" 0 "text"
+}
+
+assertNotContains()
+{
+  _assertContains "$@" 1 "text"
+}
+
+assertFileContains()
+{
+  _assertContains "$@" 0 "file"
+}
+
+assertFileNotContains()
+{
+  _assertContains "$@" 1 "file"
+}
+
+command_exists () {
+    type "$1" > /dev/null 2>&1 ;
+}
+
+assertFileMD5()
+{
+  expectedHash=$1
+  filename=$2
+
+  if command_exists "md5sum"; then
+    md5_cmd="md5sum ${filename}"
+    expected_md5_cmd_output="${expectedHash}  ${filename}"
+  elif command_exists "md5"; then
+    md5_cmd="md5 ${filename}"
+    expected_md5_cmd_output="MD5 (${filename}) = ${expectedHash}"
+  else
+    fail "no suitable MD5 hashing command found on this system"
+  fi
+
+  assertEquals "${expected_md5_cmd_output}" "`${md5_cmd}`"
+}