Add tests for docker plugin

These tests just check that the docker commands show up in the buildfile

pkg/plugin/publish/docker_test.go

@@ -0,0 +1,75 @@
+package publish
+
+import (
+    "strings"
+    "testing"
+
+    "gopkg.in/v1/yaml"
+    "github.com/drone/drone/pkg/build/buildfile"
+    "github.com/drone/drone/pkg/build/repo"
+)
+
+type PublishToDrone struct {
+    Publish *Publish `yaml:"publish,omitempty"`
+}
+
+func setUpWithDrone(input string) (string, error) {
+    var buildStruct PublishToDrone
+    err := yaml.Unmarshal([]byte(input), &buildStruct)
+    if err != nil {
+        return "", err
+    }
+    bf := buildfile.New()
+    buildStruct.Publish.Write(bf, &repo.Repo{Name: "name"})
+    return bf.String(), err
+}
+
+var missingFieldsYaml = `
+publish:
+  docker:
+    dockerfile: file
+`
+
+func TestMissingFields(t *testing.T) {
+    response, err := setUpWithDrone(missingFieldsYaml)
+    if err != nil {
+        t.Fatalf("Can't unmarshal script: %s", err.Error())
+    }
+    if !strings.Contains(response, "echo \"Docker Plugin: Missing argument(s)") {
+        t.Fatalf("Response: " + response + " didn't contain missing arguments warning")
+    }
+}
+
+var validYaml = `
+publish:
+  docker:
+    docker_file: file_path
+    docker_server: server
+    docker_port: 1000
+    docker_version: 1.0
+    repo_base_name: base_repo
+    username: user
+    password: password
+    email: email
+`
+
+func TestValidYaml(t *testing.T) {
+    response, err := setUpWithDrone(validYaml)
+    if err != nil {
+        t.Fatalf("Can't unmarshal script: %s", err.Error())
+    }
+    if !strings.Contains(response, "docker -H server:1000 build -t base_repo/name" +
+        ":$(git rev-parse --short HEAD)") {
+        t.Fatalf("Response: " + response + "doesn't contain build command")
+    }
+    if !strings.Contains(response, "docker -H server:1000 login -u user -p password -e email") {
+        t.Fatalf("Response: " + response + " doesn't contain login command")
+    }
+    if !strings.Contains(response, "docker -H server:1000 push base_repo/name") {
+        t.Fatalf("Response: " + response + " doesn't contain push command")
+    }
+    if !strings.Contains(response, "docker -H server:1000 rmi base_repo/name:" +
+        "$(git rev-parse --short HEAD)") {
+        t.Fatalf("Response: " + response + " doesn't contain remove image command")
+    }
+}