From a7619a3048968bb6186f37e9053df5aa58d1f4e8 Mon Sep 17 00:00:00 2001
From: Jonathan Bernard <jdb@jdb-labs.com>
Date: Thu, 11 May 2017 10:38:28 -0500
Subject: [PATCH] Change default value logic for stepCmd and cmdInput (see
 README).

---
 README.md                                   |  2 +-
 src/main/nim/strawbosspkg/configuration.nim | 16 +++++++++++++---
 src/test/nim/unit/tconfiguration.nim        |  2 +-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index b21d46e..9206636 100644
--- a/README.md
+++ b/README.md
@@ -125,7 +125,7 @@ Step definitions are JSON objects with the following keys:
   `'.'`, the project root directory)*.
 
 * `stepCmd` *(optional)*: the command to execute for this step. *(defaults to
-  `sh`)*
+  `true` unless `cmdInput` is given, in which case it defaults to `sh`)*
 
 * `cmdInput` *(optional)*: an array of string that will be concatenated with
   newlines separating each string and piped as input to the command for this
diff --git a/src/main/nim/strawbosspkg/configuration.nim b/src/main/nim/strawbosspkg/configuration.nim
index 8d73c33..d7f9b72 100644
--- a/src/main/nim/strawbosspkg/configuration.nim
+++ b/src/main/nim/strawbosspkg/configuration.nim
@@ -146,15 +146,25 @@ proc loadProjectConfig*(cfgFile: string): ProjectConfig =
     steps[sName] = Step(
       name:         sName,
       workingDir:   pJson.getIfExists("workingDir").getStr("."),
-      stepCmd:      pJson.getIfExists("stepCmd").getStr("sh"),
+      stepCmd:      pJson.getIfExists("stepCmd").getStr("NOT GIVEN"),
       depends:      pJson.getIfExists("depends").getElems.mapIt(it.getStr),
       artifacts:    pJson.getIfExists("artifacts").getElems.mapIt(it.getStr),
       cmdInput:     pJson.getIfExists("cmdInput").getElems.mapIt(it.getStr),
       expectedEnv:  pJson.getIfExists("expectedEnv").getElems.mapIt(it.getStr),
       dontSkip:     pJson.getIfExists("dontSkip").getBVal(false))
 
-    if steps[sName].stepCmd == "sh" and steps[sName].cmdInput.len == 0:
-      warn "Step " & sName & " uses 'sh' as its command but has no cmdInput."
+    # cmdInput and stepCmd are related, so we have a conditional defaulting.
+    # Four possibilities:
+
+    if steps[sName].stepCmd == "NOT GIVEN" and steps[sName].cmdInput.len == 0:
+      # 1. Neither given: default to no-op
+      steps[sName].stepCmd = "true"
+
+    if steps[sName].stepCmd == "NOT GIVEN" and steps[sName].cmdInput.len > 0:
+      # 2. cmdInput given but not stepCmd: default stepCmd to "sh"
+      steps[sName].stepCmd = "sh"
+
+    # 3. stepCmd given but not cmdInput & 4. both given: use them as-is
 
   result = ProjectConfig(
     name: jsonCfg.getOrFail("name", "project configuration").getStr,
diff --git a/src/test/nim/unit/tconfiguration.nim b/src/test/nim/unit/tconfiguration.nim
index 79d5dc2..6054377 100644
--- a/src/test/nim/unit/tconfiguration.nim
+++ b/src/test/nim/unit/tconfiguration.nim
@@ -100,7 +100,7 @@ suite "load and save configuration objects":
       # Step with defaulted properties
       pc.steps["test"].name == "test"
       pc.steps["test"].dontSkip == false
-      pc.steps["test"].stepCmd == "sh"
+      pc.steps["test"].stepCmd == "true"
       pc.steps["test"].workingDir == "."
       sameContents(pc.steps["test"].artifacts, @[])
       sameContents(pc.steps["test"].depends, @[])