Fix pretty for chain of compose and exclude (#1217)

Adding test for pretty print of exclude
When used with compose, the results weren't that nice.

Change: exclude-of-compose

Author: LMG

josh-core/src/filter/opt.rs

@@ -235,22 +235,30 @@ fn common_pre(filters: &Vec<Filter>) -> Option<(Filter, Vec<Filter>)> {
 
 fn common_post(filters: &Vec<Filter>) -> Option<(Filter, Vec<Filter>)> {
     let mut rest = vec![];
-    let mut c: Option<Filter> = None;
+    let mut common_post: Option<Filter> = None;
     for f in filters {
         let (a, b) = last_chain(to_filter(Op::Nop), *f);
         {
             rest.push(a);
-            if c.is_none() {
-                c = Some(b);
+            if common_post.is_none() {
+                common_post = Some(b);
             }
-            if c != Some(b) {
+            if common_post != Some(b) {
                 return None;
             }
         }
     }
-    match c.map(to_op) {
-        Some(Op::Prefix(_)) => c.map(|c| (c, rest)),
-        _ => None,
+
+    if let Some(c) = common_post {
+        if invert(c).ok() == common_post {
+            common_post.map(|c| (c, rest))
+        } else if let Op::Prefix(_) = to_op(c) {
+            common_post.map(|c| (c, rest))
+        } else {
+            None
+        }
+    } else {
+        None
     }
 }
 

tests/filter/pretty_print.t

@@ -55,6 +55,33 @@
       ::a/
       ::b/
   ]
+  $ josh-filter -p :[::a,::b]:/c
+  :[
+      ::a:/c
+      ::b:/c
+  ]
+  $ josh-filter -p :[::a,::b]::c
+  :[
+      ::a
+      ::b
+  ]::c
+Exclude of compose should not be split out
+  $ josh-filter -p :[:/a:prefix=a,:/b:prefix=b]:exclude[::a/a,::b/b]
+  :[
+      ::a/
+      ::b/
+  ]:exclude[
+      ::a/a
+      ::b/b
+  ]
+  $ josh-filter --reverse -p :[:/a:prefix=a,:/b:prefix=b]:exclude[::a/a,::b/b]
+  :exclude[
+      ::a/a
+      ::b/b
+  ]:[
+      ::a/
+      ::b/
+  ]
   $ josh-filter -p :prefix=a/b:prefix=c
   :prefix=c/a/b
   $ josh-filter --reverse -p :prefix=a/b:prefix=c