unit tests: add tests for get_system_size and get_recommend_size

Signed-off-by: Coiby Xu <coxu@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>

spec/kdump-lib_spec.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+Describe 'kdump-lib'
+	Include ./kdump-lib.sh
+
+	Describe 'get_system_size()'
+
+		PROC_IOMEM=$(mktemp -t spec_test_proc_iomem_file.XXXXXXXXXX)
+
+		cleanup() {
+			rm -rf "$PROC_IOMEM"
+		}
+
+		AfterAll 'cleanup'
+
+		ONE_GIGABYTE='000000-3fffffff : System RAM'
+		Parameters
+			1
+			3
+		End
+
+		It 'should return correct system RAM size'
+			echo -n >"$PROC_IOMEM"
+			for _ in $(seq 1 "$1"); do echo "$ONE_GIGABYTE" >>"$PROC_IOMEM"; done
+			When call get_system_size
+			The output should equal "$1"
+		End
+
+	End
+
+	Describe 'get_recommend_size()'
+		# Testing stragety:
+		# 1. inclusive for the lower bound of the range of crashkernel
+		# 2. exclusive for the upper bound of the range of crashkernel
+		# 3. supports ranges not sorted in increasing order
+
+		ck="4G-64G:256M,2G-4G:192M,64G-1T:512M,1T-:12345M"
+		Parameters
+			1 0M
+			2 192M
+			64 512M
+			1024 12345M
+			"$((64 * 1024))" 12345M
+		End
+
+		It 'should handle all cases correctly'
+			When call get_recommend_size "$1" $ck
+			The output should equal "$2"
+		End
+	End
+
+End