Templating, lower_case variables and files (#361)

* Add support for templated campaign specs

* Make search results accessible in campaign spec templates

* Remove debug log

* Remove shortcuts in templates for now

* Report rendered steps

* Remove unused parameter

* Fix build

* Add lower-case aliases and stdout/stderr to templates

* Add test to check that empty context works

* Nil-safe templates

* Mount templated files into src-cli

* WIP

* Undo local file mounting

* Allow template vars in step env

* Clean up code a little bit

* Add changelog entry

* Fix test

* Omit step.Files from CampaignSpec if empty for backwards-compatibility

* Update CHANGELOG.md

Co-authored-by: Chris Pine <[email protected]>

* Clean up temp file code

* Return slices of strings instead of whitespace-separated string

* Incorporate Adam's feedback

Co-authored-by: Chris Pine <[email protected]>

Author: mrnugget

CHANGELOG.md

@@ -13,6 +13,8 @@ All notable changes to `src-cli` are documented in this file.
 
 ### Added
 
+- EXPERIMENTAL: Templated campaign specs and file mounting. The campaign specs evaluated by `src campaign [preview|apply]` can now include template variables in `steps.run`, `steps.env`, and the new `steps.files` property, which allows users to create files inside the container in which the step is executed. The feature is marked as EXPERIMENTAL because it might change in the near future until we deem it non-experimental. See [#361](https://github.com/sourcegraph/src-cli/pull/361) for details.
+
 ### Changed
 
 ### Fixed

README.md renamed to README.markdown

@@ -66,6 +66,7 @@ type Step struct {
 	Run       string            `json:"run,omitempty" yaml:"run"`
 	Container string            `json:"container,omitempty" yaml:"container"`
 	Env       map[string]string `json:"env,omitempty" yaml:"env"`
+	Files     map[string]string `json:"files,omitempty" yaml:"files,omitempty"`
 
 	image string
 }

internal/campaigns/campaign_spec.go

@@ -98,6 +98,24 @@ func TestExecutor_Integration(t *testing.T) {
 			executorTimeout: 100 * time.Millisecond,
 			wantErrInclude:  "execution in github.com/sourcegraph/src-cli failed: Timeout reached. Execution took longer than 100ms.",
 		},
+		{
+			name:  "templated",
+			repos: []*graphql.Repository{srcCLIRepo},
+			archives: []mockRepoArchive{
+				{repo: srcCLIRepo, files: map[string]string{
+					"README.md": "# Welcome to the README\n",
+					"main.go":   "package main\n\nfunc main() {\n\tfmt.Println(     \"Hello World\")\n}\n",
+				}},
+			},
+			steps: []Step{
+				{Run: `go fmt main.go`, Container: "doesntmatter:13"},
+				{Run: `touch modified-${{ join previous_step.modified_files " " }}.md`, Container: "alpine:13"},
+				{Run: `touch added-${{ join previous_step.added_files " " }}`, Container: "alpine:13"},
+			},
+			wantFilesChanged: map[string][]string{
+				srcCLIRepo.ID: []string{"main.go", "modified-main.go.md", "added-modified-main.go.md"},
+			},
+		},
 	}
 
 	for _, tc := range tests {
@@ -170,11 +188,16 @@ func TestExecutor_Integration(t *testing.T) {
 
 				diffsByName := map[string]*diff.FileDiff{}
 				for _, fd := range fileDiffs {
-					diffsByName[fd.OrigName] = fd
+					if fd.NewName == "/dev/null" {
+						diffsByName[fd.OrigName] = fd
+					} else {
+						diffsByName[fd.NewName] = fd
+					}
 				}
+
 				for _, file := range wantFiles {
 					if _, ok := diffsByName[file]; !ok {
-						t.Errorf("%s was not changed", file)
+						t.Errorf("%s was not changed (diffsByName=%#v)", file, diffsByName)
 					}
 				}
 			}

internal/campaigns/executor_test.go

@@ -1,6 +1,9 @@
 package graphql
 
-import "strings"
+import (
+	"sort"
+	"strings"
+)
 
 const RepositoryFieldsFragment = `
 fragment repositoryFields on Repository {
@@ -30,6 +33,8 @@ type Repository struct {
 	URL                string
 	ExternalRepository struct{ ServiceType string }
 	DefaultBranch      *Branch
+
+	FileMatches map[string]bool
 }
 
 func (r *Repository) BaseRef() string {
@@ -43,3 +48,16 @@ func (r *Repository) Rev() string {
 func (r *Repository) Slug() string {
 	return strings.ReplaceAll(r.Name, "/", "-")
 }
+
+func (r *Repository) SearchResultPaths() (list fileMatchPathList) {
+	var files []string
+	for f := range r.FileMatches {
+		files = append(files, f)
+	}
+	sort.Strings(files)
+	return fileMatchPathList(files)
+}
+
+type fileMatchPathList []string
+
+func (f fileMatchPathList) String() string { return strings.Join(f, " ") }