diff tests/test-fix.t @ 40566:b9557567cc3f

fix: add suboption for configuring execution order of tools

This could be accomplished by using wrapper scripts, but that would diminish
the usefulness of the incremental formatting logic. Configuring execution order
along with other things in the hgrc is probably more convenient anyway.

This change highlights some awkwardness with suboptions and default values,
which should be addressed separately.

Differential Revision: https://phab.mercurial-scm.org/D5237

--- a/tests/test-fix.t	Wed Nov 07 14:21:39 2018 -0500
+++ b/tests/test-fix.t	Tue Nov 06 15:50:41 2018 -0800
@@ -165,6 +165,26 @@
     [fix]
     failure = abort
   
+  When multiple tools are configured to affect a file, they execute in an order
+  defined by the :priority suboption. The priority suboption has a default value
+  of zero for each tool. Tools are executed in order of descending priority. The
+  execution order of tools with equal priority is unspecified. For example, you
+  could use the 'sort' and 'head' utilities to keep only the 10 smallest numbers
+  in a text file by ensuring that 'sort' runs before 'head':
+  
+    [fix]
+    sort:command = sort --numeric-sort
+    head:command = head --lines=10
+    sort:pattern = numbers.txt
+    head:pattern = numbers.txt
+    sort:priority = 2
+    head:priority = 1
+  
+  To account for changes made by each tool, the line numbers used for
+  incremental formatting are recomputed before executing the next tool. So, each
+  tool may see different values for the arguments added by the :linerange
+  suboption.
+  
   list of commands:
   
    fix           rewrite file content in changesets or working directory
@@ -1127,3 +1147,51 @@
   first
 
   $ cd ..
+
+The execution order of tools can be controlled. This example doesn't work if
+you sort after truncating, but the config defines the correct order while the
+definitions are out of order (which might imply the incorrect order given the
+implementation of fix). The goal is to use multiple tools to select the lowest
+5 numbers in the file.
+
+  $ hg init priorityexample
+  $ cd priorityexample
+
+  $ cat >> .hg/hgrc <<EOF
+  > [fix]
+  > head:command = head --lines=5
+  > head:pattern = numbers.txt
+  > head:priority = 1
+  > sort:command = sort --numeric-sort
+  > sort:pattern = numbers.txt
+  > sort:priority = 2
+  > EOF
+
+  $ printf "8\n2\n3\n6\n7\n4\n9\n5\n1\n0\n" > numbers.txt
+  $ hg add -q
+  $ hg fix -w
+  $ cat numbers.txt
+  0
+  1
+  2
+  3
+  4
+
+And of course we should be able to break this by reversing the execution order.
+Test negative priorities while we're at it.
+
+  $ cat >> .hg/hgrc <<EOF
+  > [fix]
+  > head:priority = -1
+  > sort:priority = -2
+  > EOF
+  $ printf "8\n2\n3\n6\n7\n4\n9\n5\n1\n0\n" > numbers.txt
+  $ hg fix -w
+  $ cat numbers.txt
+  2
+  3
+  6
+  7
+  8
+
+  $ cd ..