Drain the top level internal.

This commit is contained in:
jregan
2019-10-20 15:23:25 -07:00
parent 951d15bf17
commit dee1c425da
131 changed files with 34 additions and 333 deletions

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@@ -0,0 +1,121 @@
// Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
// Package expansion provides functions find and replace $(FOO) style variables in strings.
package expansion
import (
"bytes"
"fmt"
)
const (
operator = '$'
referenceOpener = '('
referenceCloser = ')'
)
// syntaxWrap returns the input string wrapped by the expansion syntax.
func syntaxWrap(input string) string {
return string(operator) + string(referenceOpener) + input + string(referenceCloser)
}
// MappingFuncFor returns a mapping function for use with Expand that
// implements the expansion semantics defined in the expansion spec; it
// returns the input string wrapped in the expansion syntax if no mapping
// for the input is found.
func MappingFuncFor(
counts map[string]int,
context ...map[string]interface{}) func(string) interface{} {
return func(input string) interface{} {
for _, vars := range context {
val, ok := vars[input]
if ok {
counts[input]++
switch typedV := val.(type) {
case string, int64, float64, bool:
return typedV
default:
return syntaxWrap(input)
}
}
}
return syntaxWrap(input)
}
}
// Expand replaces variable references in the input string according to
// the expansion spec using the given mapping function to resolve the
// values of variables.
func Expand(input string, mapping func(string) interface{}) interface{} {
var buf bytes.Buffer
checkpoint := 0
for cursor := 0; cursor < len(input); cursor++ {
if input[cursor] == operator && cursor+1 < len(input) {
// Copy the portion of the input string since the last
// checkpoint into the buffer
buf.WriteString(input[checkpoint:cursor])
// Attempt to read the variable name as defined by the
// syntax from the input string
read, isVar, advance := tryReadVariableName(input[cursor+1:])
if isVar {
// We were able to read a variable name correctly;
// apply the mapping to the variable name and copy the
// bytes into the buffer
mapped := mapping(read)
if input == syntaxWrap(read) {
// Preserve the type of variable
return mapped
}
// Variable is used in a middle of a string
buf.WriteString(fmt.Sprintf("%v", mapped))
} else {
// Not a variable name; copy the read bytes into the buffer
buf.WriteString(read)
}
// Advance the cursor in the input string to account for
// bytes consumed to read the variable name expression
cursor += advance
// Advance the checkpoint in the input string
checkpoint = cursor + 1
}
}
// Return the buffer and any remaining unwritten bytes in the
// input string.
return buf.String() + input[checkpoint:]
}
// tryReadVariableName attempts to read a variable name from the input
// string and returns the content read from the input, whether that content
// represents a variable name to perform mapping on, and the number of bytes
// consumed in the input string.
//
// The input string is assumed not to contain the initial operator.
func tryReadVariableName(input string) (string, bool, int) {
switch input[0] {
case operator:
// Escaped operator; return it.
return input[0:1], false, 1
case referenceOpener:
// Scan to expression closer
for i := 1; i < len(input); i++ {
if input[i] == referenceCloser {
return input[1:i], true, i + 1
}
}
// Incomplete reference; return it.
return string(operator) + string(referenceOpener), false, 1
default:
// Not the beginning of an expression, ie, an operator
// that doesn't begin an expression. Return the operator
// and the first rune in the string.
return string(operator) + string(input[0]), false, 1
}
}

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// Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
package expansion_test
import (
"fmt"
"testing"
. "sigs.k8s.io/kustomize/v3/api/internal/accumulator/expansion"
)
type expected struct {
count int
edited string
}
func TestMapReference(t *testing.T) {
type env struct {
Name string
Value interface{}
}
envs := []env{
{
Name: "FOO",
Value: "bar",
},
{
Name: "ZOO",
Value: "$(FOO)-1",
},
{
Name: "BLU",
Value: "$(ZOO)-2",
},
{
Name: "INT",
Value: 2,
},
{
Name: "ZINT",
Value: "$(INT)",
},
{
Name: "BOOL",
Value: true,
},
{
Name: "ZBOOL",
Value: "$(BOOL)",
},
}
declaredEnv := map[string]interface{}{
"FOO": "bar",
"ZOO": "$(FOO)-1",
"BLU": "$(ZOO)-2",
"INT": "2",
"ZINT": "$(INT)",
"BOOL": "true",
"ZBOOL": "$(BOOL)",
}
counts := make(map[string]int)
mapping := MappingFuncFor(counts, declaredEnv)
for _, env := range envs {
declaredEnv[env.Name] = Expand(fmt.Sprintf("%v", env.Value), mapping)
}
expectedEnv := map[string]expected{
"FOO": {count: 1, edited: "bar"},
"ZOO": {count: 1, edited: "bar-1"},
"BLU": {count: 0, edited: "bar-1-2"},
"INT": {count: 1, edited: "2"},
"ZINT": {count: 0, edited: "2"},
"BOOL": {count: 1, edited: "true"},
"ZBOOL": {count: 0, edited: "true"},
}
for k, v := range expectedEnv {
if e, a := v, declaredEnv[k]; e.edited != a || e.count != counts[k] {
t.Errorf("Expected %v count=%d, got %v count=%d",
e.edited, e.count, a, counts[k])
} else {
delete(declaredEnv, k)
}
}
if len(declaredEnv) != 0 {
t.Errorf("Unexpected keys in declared env: %v", declaredEnv)
}
}
func TestMapping(t *testing.T) {
context := map[string]interface{}{
"VAR_A": "A",
"VAR_B": "B",
"VAR_C": "C",
"VAR_REF": "$(VAR_A)",
"VAR_EMPTY": "",
}
doExpansionTest(t, context)
}
func TestMappingDual(t *testing.T) {
context := map[string]interface{}{
"VAR_A": "A",
"VAR_EMPTY": "",
}
context2 := map[string]interface{}{
"VAR_B": "B",
"VAR_C": "C",
"VAR_REF": "$(VAR_A)",
}
doExpansionTest(t, context, context2)
}
func doExpansionTest(t *testing.T, context ...map[string]interface{}) {
cases := []struct {
name string
input string
expected string
counts map[string]int
}{
{
name: "whole string",
input: "$(VAR_A)",
expected: "A",
counts: map[string]int{"VAR_A": 1},
},
{
name: "repeat",
input: "$(VAR_A)-$(VAR_A)",
expected: "A-A",
counts: map[string]int{"VAR_A": 2},
},
{
name: "multiple repeats",
input: "$(VAR_A)-$(VAR_B)-$(VAR_B)-$(VAR_B)-$(VAR_A)",
expected: "A-B-B-B-A",
counts: map[string]int{"VAR_A": 2, "VAR_B": 3},
},
{
name: "beginning",
input: "$(VAR_A)-1",
expected: "A-1",
counts: map[string]int{"VAR_A": 1},
},
{
name: "middle",
input: "___$(VAR_B)___",
expected: "___B___",
counts: map[string]int{"VAR_B": 1},
},
{
name: "end",
input: "___$(VAR_C)",
expected: "___C",
counts: map[string]int{"VAR_C": 1},
},
{
name: "compound",
input: "$(VAR_A)_$(VAR_B)_$(VAR_C)",
expected: "A_B_C",
counts: map[string]int{"VAR_A": 1, "VAR_B": 1, "VAR_C": 1},
},
{
name: "escape & expand",
input: "$$(VAR_B)_$(VAR_A)",
expected: "$(VAR_B)_A",
counts: map[string]int{"VAR_A": 1},
},
{
name: "compound escape",
input: "$$(VAR_A)_$$(VAR_B)",
expected: "$(VAR_A)_$(VAR_B)",
},
{
name: "mixed in escapes",
input: "f000-$$VAR_A",
expected: "f000-$VAR_A",
},
{
name: "backslash escape ignored",
input: "foo\\$(VAR_C)bar",
expected: "foo\\Cbar",
counts: map[string]int{"VAR_C": 1},
},
{
name: "backslash escape ignored",
input: "foo\\\\$(VAR_C)bar",
expected: "foo\\\\Cbar",
counts: map[string]int{"VAR_C": 1},
},
{
name: "lots of backslashes",
input: "foo\\\\\\\\$(VAR_A)bar",
expected: "foo\\\\\\\\Abar",
counts: map[string]int{"VAR_A": 1},
},
{
name: "nested var references",
input: "$(VAR_A$(VAR_B))",
expected: "$(VAR_A$(VAR_B))",
},
{
name: "nested var references second type",
input: "$(VAR_A$(VAR_B)",
expected: "$(VAR_A$(VAR_B)",
},
{
name: "value is a reference",
input: "$(VAR_REF)",
expected: "$(VAR_A)",
counts: map[string]int{"VAR_REF": 1},
},
{
name: "value is a reference x 2",
input: "%%$(VAR_REF)--$(VAR_REF)%%",
expected: "%%$(VAR_A)--$(VAR_A)%%",
counts: map[string]int{"VAR_REF": 2},
},
{
name: "empty var",
input: "foo$(VAR_EMPTY)bar",
expected: "foobar",
counts: map[string]int{"VAR_EMPTY": 1},
},
{
name: "unterminated expression",
input: "foo$(VAR_Awhoops!",
expected: "foo$(VAR_Awhoops!",
},
{
name: "expression without operator",
input: "f00__(VAR_A)__",
expected: "f00__(VAR_A)__",
},
{
name: "shell special vars pass through",
input: "$?_boo_$!",
expected: "$?_boo_$!",
},
{
name: "bare operators are ignored",
input: "$VAR_A",
expected: "$VAR_A",
},
{
name: "undefined vars are passed through",
input: "$(VAR_DNE)",
expected: "$(VAR_DNE)",
},
{
name: "multiple (even) operators, var undefined",
input: "$$$$$$(BIG_MONEY)",
expected: "$$$(BIG_MONEY)",
},
{
name: "multiple (even) operators, var defined",
input: "$$$$$$(VAR_A)",
expected: "$$$(VAR_A)",
},
{
name: "multiple (odd) operators, var undefined",
input: "$$$$$$$(GOOD_ODDS)",
expected: "$$$$(GOOD_ODDS)",
},
{
name: "multiple (odd) operators, var defined",
input: "$$$$$$$(VAR_A)",
expected: "$$$A",
counts: map[string]int{"VAR_A": 1},
},
{
name: "missing open expression",
input: "$VAR_A)",
expected: "$VAR_A)",
},
{
name: "shell syntax ignored",
input: "${VAR_A}",
expected: "${VAR_A}",
},
{
name: "trailing incomplete expression not consumed",
input: "$(VAR_B)_______$(A",
expected: "B_______$(A",
counts: map[string]int{"VAR_B": 1},
},
{
name: "trailing incomplete expression, no content, is not consumed",
input: "$(VAR_C)_______$(",
expected: "C_______$(",
counts: map[string]int{"VAR_C": 1},
},
{
name: "operator at end of input string is preserved",
input: "$(VAR_A)foobarzab$",
expected: "Afoobarzab$",
counts: map[string]int{"VAR_A": 1},
},
{
name: "shell escaped incomplete expr",
input: "foo-\\$(VAR_A",
expected: "foo-\\$(VAR_A",
},
{
name: "lots of $( in middle",
input: "--$($($($($--",
expected: "--$($($($($--",
},
{
name: "lots of $( in beginning",
input: "$($($($($--foo$(",
expected: "$($($($($--foo$(",
},
{
name: "lots of $( at end",
input: "foo0--$($($($(",
expected: "foo0--$($($($(",
},
{
name: "escaped operators in variable names are not escaped",
input: "$(foo$$var)",
expected: "$(foo$$var)",
},
{
name: "newline not expanded",
input: "\n",
expected: "\n",
},
}
for _, tc := range cases {
counts := make(map[string]int)
mapping := MappingFuncFor(counts, context...)
expanded := Expand(fmt.Sprintf("%v", tc.input), mapping)
if e, a := tc.expected, expanded; e != a {
t.Errorf("%v: expected %q, got %q", tc.name, e, a)
}
if len(counts) != len(tc.counts) {
t.Errorf("%v: len(counts)=%d != len(tc.counts)=%d",
tc.name, len(counts), len(tc.counts))
}
if len(tc.counts) > 0 {
for k, expectedCount := range tc.counts {
c, ok := counts[k]
if ok {
if c != expectedCount {
t.Errorf(
"%v: k=%s, expected count %d, got %d",
tc.name, k, expectedCount, c)
}
} else {
t.Errorf(
"%v: k=%s, expected count %d, got zero",
tc.name, k, expectedCount)
}
}
}
}
}