Break searching / error handling for standard directory structure into auxiliary file / struct

1 files changed, 177 insertions, 0 deletions

diff --git a/stddirs.go b/stddirs.go
new file mode 100644
index 0000000..adefce8
--- /dev/null
+++ b/stddirs.go
@@ -0,0 +1,177 @@
+package planr
+
+import (
+  "os"
+  "log"
+  "path"
+  "path/filepath"
+)
+
+// Standard Directories:
+//
+// Planr relies on a standard directory structure to resolve paths to source code
+// These directories can be overridden via environmental variables //
+// Directories:
+// - `.`            root directory
+// - `src`          contains source code
+// - `planr`        contains test metadata (also called configuration directory)
+// - `planr/rubric` contains test case configuration
+// - `planr/tests`  contains source code for test cases
+// - `planr/build`  contains all files written during the build process (ephemeral)
+
+// Env overrides
+const (
+  ENV_CONFIG_DIR="PLANR_PLANR_DIR"
+  ENV_SRC_DIR="ENV_SRC_DIR"
+  ENV_BUILD_DIR="PLANR_BUILD_DIR"
+)
+
+// Try these search directories
+var CONFIG_SEARCH_DIRS = [2] string {
+  "planr",
+  ".planr",
+}
+
+// Path are relative to the "planr" project config directory
+const (
+  DEFAULT_PATH_SRC="../src"
+  DEFAULT_PATH_BUILD="build"
+  DEFAULT_PATH_RUBRIC="rubric"
+  DEFAULT_PATH_TESTS="tests"
+)
+
+type dirConfig struct {
+  src    string
+  config string
+  build  string
+}
+
+func dieDirAbsent(name, path string) {
+  if !directoryExists(path) {
+    log.Fatalf("Could not find %s directory tried %s", name, path)
+  }
+}
+
+func dirFromEnv(name, env string) *string {
+  if dir, isSet := os.LookupEnv(env); isSet {
+    
+    dieDirAbsent(name, dir)
+
+    return &dir
+  }
+
+  return nil
+}
+
+func (c *dirConfig) SetSrcDir(srcDir string) {
+  dieDirAbsent("src", srcDir)
+  c.src = srcDir
+}
+
+func (c *dirConfig) SetConfigDir(configDir string) {
+  dieDirAbsent("planr (config)", configDir)
+  c.config = configDir
+}
+
+func (c *dirConfig) SetBuildDir(buildDir string) {
+  dieDirAbsent("build", buildDir)
+  c.build = buildDir
+}
+
+func (c *dirConfig) SetConfigDirFromTree(cdir string) {
+  var configDir string
+
+  found := traverseUp(cdir, func (path string) bool {
+
+    for _, dir := range CONFIG_SEARCH_DIRS {
+      configDir = filepath.Join(path, dir)
+      
+      if directoryExists(configDir) {
+        return true
+      }
+    }
+
+    return false 
+  });
+
+  if !found {
+    log.Fatal("Could not find planr directory");
+  }
+
+  c.config = configDir
+}
+
+func (c dirConfig) ConfigDir() string {
+  if c.config != "" {
+    return c.config
+  }
+
+  dir := dirFromEnv("config", ENV_CONFIG_DIR)
+  if dir == nil {
+    log.Fatal("Could not find directory")
+  }
+
+  c.config = *dir
+  return c.config
+}
+
+func (c dirConfig) SrcDir() string {
+  if c.src != "" {
+    return c.src
+  }
+
+  if dir := dirFromEnv("src", ENV_SRC_DIR); dir != nil {
+    c.src = *dir
+    return c.src
+  }
+
+  // set path relative to config
+  dir := c.ConfigDir()
+  return path.Join(dir, DEFAULT_PATH_SRC)
+}
+
+func (c dirConfig) BuildDir() string {
+  if c.src != "" {
+    return c.src
+  }
+
+  if dir := dirFromEnv("build", ENV_BUILD_DIR); dir != nil {
+    c.build = *dir
+    return c.build
+  }
+
+  dir := c.ConfigDir()
+  return path.Join(dir, DEFAULT_PATH_BUILD)
+}
+
+func (c dirConfig) CleanBuildDir() {
+  build := c.BuildDir()
+
+  if err := os.RemoveAll(build); err != nil {
+    log.Fatalf("Cannot build directory %v\n", err)
+  }
+  
+  if err := os.Remove(build); err != nil {
+    log.Fatalf("Could not remove build directory %v\n", err)
+  }
+}
+
+func (c dirConfig) MkBuildDir() {
+  build := c.BuildDir()
+
+  if err := os.Mkdir(build, 0755); err != nil {
+    log.Fatalf("Could not create build directory %v\n", err)
+  }
+}
+
+func (c dirConfig) RubricDir() string {
+  rubric := path.Join(c.ConfigDir(), "rubric")
+  dieDirAbsent("rubric", rubric)
+  return rubric
+}
+
+func (c dirConfig) TestsDir() string {
+  tests := path.Join(c.ConfigDir(), "tests")
+  dieDirAbsent("tests", tests)
+  return tests
+}