Error Message Polishing

This change updates the error message polishing to describe the amount of
memory required by the application in order to run.

[paketo-buildpacks/libjvm#4]

Signed-off-by: Ben Hale <[email protected]>

Author: nebhale

calculator/calculator.go

@@ -73,8 +73,8 @@ func (c Calculator) Calculate() ([]fmt.Stringer, error) {
 	available := memory.Size(*c.TotalMemory)
 
 	if overhead > available {
-		return nil, fmt.Errorf("allocated memory is greater than %s available for allocation: %s, %s, %s, %s x %d threads",
-			available, directMemory, metaspace, reservedCodeCache, stack, *c.ThreadCount)
+		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s, %s x %d threads",
+			overhead, available, directMemory, metaspace, reservedCodeCache, stack, *c.ThreadCount)
 	}
 
 	heap := j.MaxHeap
@@ -85,8 +85,8 @@ func (c Calculator) Calculate() ([]fmt.Stringer, error) {
 	}
 
 	if overhead+memory.Size(*heap) > available {
-		return nil, fmt.Errorf("allocated memory is greater than %s available for allocation: %s, %s, %s, %s, %s x %d threads",
-			available, directMemory, heap, metaspace, reservedCodeCache, stack, *c.ThreadCount)
+		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s, %s, %s x %d threads",
+			overhead+memory.Size(*heap), available, directMemory, heap, metaspace, reservedCodeCache, stack, *c.ThreadCount)
 	}
 
 	return options, nil

go.mod

@@ -1,11 +1,13 @@
 module github.com/cloudfoundry/java-buildpack-memory-calculator
 
+go 1.14
+
 require (
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/onsi/ginkgo v1.7.0 // indirect
 	github.com/onsi/gomega v1.4.3
 	github.com/sclevine/spec v1.2.0
-	github.com/spf13/pflag v1.0.3
+	github.com/spf13/pflag v1.0.5
 	golang.org/x/net v0.0.0-20181217023233-e147a9138326 // indirect
 	golang.org/x/sync v0.0.0-20181108010431-42b317875d0f // indirect
 	golang.org/x/sys v0.0.0-20181218192612-074acd46bca6 // indirect

go.sum

@@ -16,8 +16,8 @@ github.com/onsi/gomega v1.4.3 h1:RE1xgDvH7imwFD45h+u2SgIfERHlS2yNG4DObb5BSKU=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/sclevine/spec v1.2.0 h1:1Jwdf9jSfDl9NVmt8ndHqbTZ7XCCPbh1jI3hkDBHVYA=
 github.com/sclevine/spec v1.2.0/go.mod h1:W4J29eT/Kzv7/b9IWLB055Z+qvVC9vt0Arko24q7p+U=
-github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
-github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd h1:nTDtHvHSdCn1m6ITfMRqtOd/9+7a3s8RBNOZ3eYZzJA=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181217023233-e147a9138326 h1:iCzOf0xz39Tstp+Tu/WwyGjUXCk34QhQORRxBeXXTA4=